The obs_source::async_reset_texture variable can cause a data race
between threads to occur because it could be set to true in one thread
then changed back to false in another thread.  This could cause the
async texture to not update its size when it's supposed to, which can
cause a crash or corruption when copying data from a frame of a
differing size.

The solution to this is to:

- Delete the async_reset_texture variable, and make the
  set_async_texture_size function change the texture size if the
  async_width, async_height, or async_format variables differ from the
  frame's width/height/format.  Those variables are then only ever set
  in the libobs graphics thread.

- Make the cache_video function use separate variables from other
  functions to detect a change in size (due to the fact that the texture
  size should only be resized in the libobs graphics thread).  These
  variables are async_cache_width, async_cache_height, and
  async_cache_format, which are only be set in the thread that calls
  obs_source_output_video.

How to replicate the data race:

- On OSX, use window capture on a textedit window, then continually
  resize the textedit window.

This comment was originally for an older version of the code; I'm
guessing I forgot to remove it along with the code that it originally
belonged with.

Changes:
- Prevent concurrent calls to EnumDevices (resolves a crash with
  some device filters (like the XCAPTURE-1) with multiple active
  dshow sources)

Fix warning encountered on clang-504.0.40 on OSX 10.9:

obs/window-basic-main.cpp:2884:22: warning: suggest braces around
initialization of subobject [-Wmissing-braces]
		struct vec2 dir = {0.0f, 0.0f};

The bilinear lowres scale effect was using 'output' for a variable,
which is apparently a reserved keyword in GLSL on macs.  This slipped
by me due to the fact that this didn't occur with OpenGL on my windows
machine.

Fix an issue where effects that fail to compile will not properly free
their data if they cannot not be parsed or compiled.

Adds an icon to the executable file so the executable no longer shows up
without an icon.

Add the ability to use a fullscreen projector for scenes, sources, and
the preview display.

This allows viewing a source, scene, or the main preview in a fullscreen
window.

Allows nudging of selected items in the direction pressed when the
preview window is focused.

Includes the ability to disable the preview and general source context
menu options (add/remove/filters/properties/etc)

If the item currently selected in the source listbox is deselected in
the preview, then make sure to deselect it in the listbox as well.

These are replaced by other settings in the global ini file.

Rather than using [MainWindow] in the global ini, explicitly state
BasicWindow instead so we know it's for the basic user interface.

Allows selection of items by right-clicking on the preview as well
rather than just left-clicks.

Adds the following changes:
- Prioritize YUV formats over non-YUV formats for performance and to
  prevent intermediary filters
- Directly connect filters when possible to avoid intermediary filters

Fix an issue where if the FPS property is set to "Match Output FPS" it
will not show all the available video formats.

The WaitForSignal message is supposed to return return true if the
handle was signaled, not if the wait timed out.

Fixes an issue where if the device can't be connected, it will
continually repeat the connection failure message.

When frames were dropped, it would also drop I-frames, which can mess
with the keyframe calculation of certain services that depend on
I-frames in their output protocol (such as HLS).

The minimum and maximum color range values were not being set by the
video_format_get_parameters function when full range was in use; I
assume it's because the expected min/max values of full range is
{0.0, 0.0, 0.0} and {1.0, 1.0, 1.0}, so I'm just making it so that it
sets those values if using full range.

Way to replicate the issue (windows):
1.) Create a win-dshow device capture source
2.) Select a device and set it to a YUV color format to enable YUV color
conversion
3.) Select "Full Range" in the color range property.
4.) Restart OBS, the device will then start up, but will display green
due to the fact that the min/max range values were never set, and are
left at their default value of 0.

Due to a bad 'if' expression, when a filter that is not last in the
chain is disabled or being bypassed, it ends up still calling the
filter's video processing function unintentionally.

This fix makes sure that it only calls the appropriate render functions
if the next filter target is the source, otherwise it will just call
obs_source_video_render to process the next filter in the chain.

How to replicate the bug:
1. Create two crop filters on the same source
2. Give each crop filter a different distinct value
3. Disable both crop filters
4. The image would still be cropped

The normal scaling methods cannot sample enough pixels to create an
accurate output image when the output size is under half the base size,
so use the bilinear low resolution scaling effect in that case instead
to ensure a more accurate low resolution image.

This effect preserves detail of images that are scaled below half size
by using sampling 9 pixels.

Add missing function definitions for the lanczos and bicubic effects

This function sets the background color for a display

If you don't need to see what's displayed, then this is particularly
useful for two reasons:
1. It reduces the number of draw/present calls
2. It can prevent issues with certain hardware setups where rendering on
   a monitor hooked up to a separate card can experience slowdowns

Sometimes it can be useful to turn off rendering to the display in order
to reduce the number of draw calls and present calls.

Use std::abs instead of abs to avoid loss in precision and also fix
the corresponding warning from clang (3.5.0):

warning: using integer absolute value function 'abs' when argument is
of floating point type [-Wabsolute-value]

Closes jp9000/obs-studio#414

NixOS installation instructions

Buildfix for older FFmpeg versions (F20 RPMFusion)

The buffer size was being saved as 'VBufsize' while all read operations
tried to read 'Bufsize'

This reverts commit 99c674e4.

These commits were originally added to allow multiple user interfaces to
use the same plugins, but I soon realized that multiple user interfaces
can use multiple libobs versions, so each user interface should have its
own set of plugins to manage.  Some user interfaces may not wish to use
certain plugins anyway, so this fixes that issue as well.

This reverts commit 92d800cc, reversing
changes made to 35a4aced.

These commits were originally added to allow multiple user interfaces to
use the same plugins, but I soon realized that multiple user interfaces
can use multiple libobs versions, so each user interface should have its
own set of plugins to manage.  Some user interfaces may not wish to use
certain plugins anyway, so this fixes that issue as well.

Add $HOME/.obs-plugins as default module search dir on Linux

When display capture is created, the hide_cursor variable is not
initialized, so just initialize it to the setting in the create
function.

The kCGDisplayStreamShowCursor option used with the dictionary does not
work if you assign @true or @false to it.  After some testing, it needs
to point to the id cast of either kCFBooleanTrue or kCFBooleanFalse in
order for it to work properly.

If it doesn't use either of those values, the display stream seems to
use its internal default, which on 10.8 and 10.9 is visible, and 10.10+
is invisible, which would explain why people on 10.10 couldn't get the
cursor to capture.