This commit fixes a bug where the user would have to restart OBS when
certain types of devices are unplugged and plugged back in again
(particularly USB devices).  A wait interval is required
(RECONNECT_INTERVAL) because Windows does not send any events to
IAudioCaptureClient on device invalidation.

Fixes an issue where COM might not be available to calls within the
reconnect thread.

libobs: UI: Fix rotated line scale

UI: Remove SourceListWidget

UI: Fix Linux build without PulseAudio

Improve ffmpeg output error handling

UI: Volume scrollEvents

This commit fixes the issue of being able to scroll through the mixer
with the mouse wheel without modifying the volume slider.  This
functionality can be temporarily restored by holding a click on the
volume meter.

The line drawing functions previously assumed the upper-left 3x3 for
box_transform only held scale. The matrix can also hold rotation, so
pass in scale separately.

Fixes https://obsproject.com/mantis/view.php?id=1442

Decklink: preview out support

Windows is a product name in this case.

libobs/UI: Add Property Grouping

Property groups are implemented in the UI using QGroupBox, which support
both the normal and checkable version of them.

Property groups allow multiple properties to be combined into a single
visual group and thus can be used to reduce visual clutter and improve
user experience by giving additional context to a property. The name of
a child of a group is not affected by the group and thus all property
names must still be unique.

A new parent field has been added to obs_properties_t to ease the
tracking of existing properties. That way properties inside a group will
also be able to verify that they have a unique name.

UI: Correct custom property implementation

Don't override the theme color settings for the Projector.
If required, the background color of the projector can be changed via

OBSProjector {qproperty-...}

record placed after "OBSQTDisplay {qproperty-...}" section in the theme
file (qss).

- Fixes Q_PROPERTY macro syntax
- Removes excessive notification declaration and slot
- Removes unneeded dynamic property
- Improves Themes versatility

vlc-video: Enable subtitle track selection

If custom theme for obs UI has no record about background custom
property in the qss file, then application can set random color per
display initialization. This fixes this issue.

Commit 31d36691 missed updating a couple of lines while moving
settings around.

- https://github.com/obsproject/obs-studio/commit/31d36691

deps/obs-scripting: Expose obs_output_output_caption_text1 to scripts

libobs: Fix shader for GLSL

vec4 to vec3 truncation fix.

Ui scroll wheel events

libobs: Add support for F25-F35 hotkeys on Linux

libobs: Add function to remove properties

vlc-video: Enable audio track selection

UI: Add Linux AppStream metadata

Improve locales

UI: Add hotkey to toggle preview