- Implement the RTMP output module.  This time around, we just use a
   simple FLV muxer, then just write to the stream with RTMP_Write.
   Easy and effective.

 - Fix the FLV muxer, the muxer now outputs proper FLV packets.

 - Output API:
   * When using encoders, automatically interleave encoded packets
     before sending it to the output.

   * Pair encoders and have them automatically wait for the other to
     start to ensure sync.

   * Change 'obs_output_signal_start_fail' to 'obs_output_signal_stop'
     because it was a bit confusing, and doing this makes a lot more
     sense for outputs that need to stop suddenly (disconnections/etc).

 - Encoder API:
   * Remove some unnecessary encoder functions from the actual API and
     make them internal.  Most of the encoder functions are handled
     automatically by outputs anyway, so there's no real need to expose
     them and end up inadvertently confusing plugin writers.

   * Have audio encoders wait for the video encoder to get a frame, then
     start at the exact data point that the first video frame starts to
     ensure the most accrate sync of video/audio possible.

   * Add a required 'frame_size' callback for audio encoders that
     returns the expected number of frames desired to encode with.  This
     way, the libobs encoder API can handle the circular buffering
     internally automatically for the encoder modules, so encoder
     writers don't have to do it themselves.

 - Fix a few bugs in the serializer interface.  It was passing the wrong
   variable for the data in a few cases.

 - If a source has video, make obs_source_update defer the actual update
   callback until the tick function is called to prevent threading
   issues.

Caused D3D11 library to fail on load.  Don't know how I didn't see this
sooner.

Someone got rather confused over what the "default" functions did, so
hopefully this clears it up a bit.

I was getting cases where the CPU cache was causing issues with the
allocation counter, for the longest time I thought I was doing something
wrong, but when the allocation counter went below 0, I realized it was
because I didn't use atomics for incrementing/decrementing the
allocation counter variable.  The allocation counter now always should
have the correct value.

Now that we have the priorties window in we can finally be able to
select windows for capture source such as window capture.  Only took
about an hour or two to write.

Also, fixed some depednency issues on winmm.lib with obs-outputs

More extensions, less bugs

Added GLX_NV_copy_image extension, updated tools

Add compatiblity for some older ffmpeg versions

...I think I need sleep.  That last commit before this one shows it
quite clearly.

Accidentally removed a function from the main module declaration macro.

Instead of doing this, just use macros to handle this situation.

Also, fix a minor bug in AAC encoder

This just adds FFmpeg's default AAC encoder as an audio encoder.  Going
to try to start getting things going with the RTMP output library next.

 - Add interleaving of video/audio packets for outputs that are encoded
   and expect both video and audio data, sorting the packets and sending
   them to the output when both video and audio is received.

 - Combine create and initialize callbacks for the encoder API callback
   interface.

Improve the properties API so that it can actually respond somewhat to
user input.  Maybe later this might be further improved or replaced with
something script-based.

When creating a property, you can now add a callback to that property
that notifies when the property has been changed in the user interface.
Return true if you want the properties to be refreshed, or false if not.
Though now that I think about it I doubt there would ever be a case
where you would have this callback and *not* refresh the properties.

Regardless, this allows functions to change the values of properties or
settings, or enable/disable/hide other property controls from view
dynamically.

1) Fixed the preview window. It now correctly displays the source.
2) The GLX backend now correctly uses the devices current swap.
3) We now set device->cur_swap to a default so we don't have to check it in every function.
4) Minor syntactical cleanups and perhaps some messiness added.

This unfortunately re-introduces undesirable rendering behaviour for
slow renderers (e.g. first gen Intel HD graphics/Apple software
renderer) when the property window is open, but fixes property window
preview rendering for sufficiently fast renderers

Remove unneeded assignment from previous code.

Fix gswindow display with Qt

 - Add start/stop code to obs-output module

 - Use a circular buffer for the buffered encoder packets instead of a
   dynamic array

 - Add pthreads.lib as a dependency to obs-output module on windows in
   visual studio project files

 - Fix an windows export bug for avc parsing functions on windows.
   Also, rename those functions to be more consistent with each other.

 - Make outputs use a single function for encoded data rather than
   multiple functions

 - Add the ability to make 'text' properties be passworded

Several CMake fixes and enhancements

This is mainly intended to be used for preloaded/injected DLLs, which
don't belong into the libdir or plugindir.