libobs: Rework code for checking Mac audio device capabilities for mo…

Allows the ability to show a web page via CEF to the users on startup to
present and announce new features.

Adds a very basic and easy-to-use C++ library strictly for the sake of
convenience when using C++.

Currently the only thing preventing a user from trying to start multiple
streams or recordings is the UI buttons being disabled. The hotkey code
allowed the user to bypass that, which for streaming resulted in lots of
rtmp output connect threads spawning, which stomped all over each
other's data structures and resulted in crashes.

OSX: Add NSCamera and NSMicrophone UsageDescription for 10.14

Fix typo in contributor guide

rtmp-services: Add Piczel.TV server

CI: Update to Qt 5.11.1

UI: Fix start up crash with saved projectors

This fixes a crash in case the user selected the option to save
projectors on exit and had multiple monitors at that time. Later on,
when obs is started again if the monitor list is lower now the open
projector code will return null when trying to create the saved
projector.

Just check if the returned projector pointer is valid before trying
to restore the saved geometry.

Piczel.TV is a streaming and art gallery website - https://piczel.tv

Due to the recent change in which scene items now only update their
transforms during the next frame's tick, snapping sources would
sometimes jitter and have incorrect snapping.  This fixes that issue by
reverting to the behavior of updating the transform immediately rather
than deferring the update to the next frame tick, but only on non-group
items.

This should not be done on items that are sub-items of groups because we
rely on the obs_scene_item::update_transform variable to update the
parent group's transform in addition.

Instead of updating the scene item texture any time
update_item_transform() is called, only update it when
obs_scene_item::update_transform is called.  Prevents having to lock the
graphics mutex needlessly.

On initial creation of an empty group, do not open a properties dialog
for groups.

Mostly security / reliability related, fixing various access to
uninitialized data, integer overflows, etc from
https://git.ffmpeg.org/rtmpdump

CI: Add AppVeyor webhook for Discord bot

CI: Add travis webhook URL for Discord bot

Adds the ability to set the current palette for the program via adding
"OBSTheme" objects to the qss files.  The values for the OBSTheme object
are the values used by QPalette::ColorRole.

Modifying the global palette allows the ability to easily/quickly look
up application theme colors (especially if you would like to use them
for QML), as well as the ability to fix the hyperlink color issue.  (On
dark themes, links would still be dark blue, causing them to be
difficult to see)

obs-output: Update ftl-sdk version

As of commit 2eb5a228, CoreAudio devices that use one device handle for
both input and output can no longer be used for audio monitoring. This
commit fixes that.

Tested with the built-in output, a Magewell XI100DUSB-HDMI which is
input only, and a MOTU UltraLite audio interface, which shows as
output/input capable.

When the user had advanced output mode selected and they created a new
profile, enforced service settings for advanced output mode would not be
applied because GetDataFromJsonFile would return a nullptr (because the
settings file did not yet exist).  Instead of returning nullptr, always
return a valid data object, and in addition, apply the defaults of the
encoder to pass to obs_service_apply_encoder_settings just to be safe.

Rather than relying on the encoder's type identifier, additionally allow
the ability to get defaults via an encoder object.

Fixes an error and a warning when compiling with experimental shared
texture support.

If the scene item crop/filtering is updated, instead of
creating/destroying the item texture on the spot, update it in the
graphics thread to prevent potential race conditions (especially when
the crop function for example could be called from within
obs_scene_enum_items in some situations, which would lock the graphics
and scene mutexes in the wrong order).

Allows the use of alt-cropping on scene items that have bounding box
enabled.  The crop will simply apply to the source within the bounding
box rather than try to do anything fancy.  A simple solution to an
annoying problem.

Instead, just check to see whether array and num are valid, and if they
are not, safely return.

Allow multiple QSV encoders, usefull for live + recorded parallel
sessions.  The first QSV encoder will create a DirectX device and return
a handle / pointer.  Any additional QSV encoder will use that same
pointer to the DirectX device.  We keep track of the number of open
QSV encoders so that we wait to close the DirectX resources after all
encoders are closed.

Closes obsproject/obs-studio#1341