Adds a virtual camera button to the main user interface.  If virtual
camera is not installed, it will not add the button.  On Windows, it
detects whether the virtual camera filters are properly registered, and
will only add the button if the virtual camera filter is confirmed
registered.

Also adds a virtual camera option to the auto-configuration wizard,
which will just simply set the user's resolution/scale to 1920x1080 at
30 FPS.

Closes obsproject/obs-studio#2290

(This commit also modifies the UI)

Adds the ability to schedule tasks for certain threads

This requires CEF >= 3683

Fixes #2194

This fixes some crashes in browser panels on Mac, but it's also harmless
if browser panels aren't enabled.

This param is the buffer size, including null terminator

The last parameter is the buffer size (which would include null
terminator), not the desired string length.

This change makes it so OBS will still launch even if a theme is
missing. This change also deprecates the "CurrentTheme" config key, and
is replaced by "CurrentTheme2".

This is because a previous change to make sure OBS fell back to the
System theme in case of a missing theme had been accidentally removed.
Changing the key prevents a new version of OBS setting a theme that
doesn't exist in an older version, which would prevent that version from
launching.

Both BTTV and FFZ are fairly popular however they do occasionally
interfere.  To give users the option to chose whichever one they like
most we add a new setting that allows BTTV, FFZ, both, or neither.

Defaults to "None" for new users.  Existing users will be migrated to
"Both" as that's the previous behavior.

(This commit also modifies the UI)

This solves the issue where OBS would be deprioritized by Windows over
fullscreen games, causing OBS to lag out whereas the games would still
run fine.

This reverts commit b5843caa.

This breaks some hotkeys because the signals are tied to a signal which
is now triggered because "toggled" is used instead of "clicked", so just
revert it for now for the release and look at it later post-patch.

This commit fixes various issues with screen readers in the main OBS
interface. These were tested using NVDA on Windows 10 1903.

Checkboxes or buttons which toggle, when receiving an activate signal
from the screen reader would visually update, but not perform any
action. This is because they're listening only for clicks. They should
all now be listening for toggles instead.

The screen reader would navigate through the UI in the order that
elements are defined in the .ui XML, and not by their row positions.
The XML has been reordered so that things should be defined in their row
order.

Audio track selection now says Track 1, 2, etc, rather than just the
number. Various checkboxes that just say "Enable" now have accessible
text that says what the enable is for (since it says "checkbox", the
fact it's an enable should hopefully be clear). Type in the recording
tab of output now has accessible text which says "Recording Type".

All the right side buttons in hotkeys now have tooltips, and by
extension, accessible text. Currently it does not yet say what hotkey
the action is in relation to, but that would require more locales.

The parameter "inFocus" was being given the opposite of what the name
implies: it was being set to false when in focus, and true when not in
focus.  This fixes that confusion.

Fixes a bug where the hotkey inject would trigger hotkeys despite
hotkeys being disabled when in focus.

Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed.  Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.

This can happen when trying to write to a closed socket (in the case
of an RTMP server closing the connection).

Fixes: https://obsproject.com/mantis/view.php?id=1446

Without this, we strcmp a null pointer if no theme is set in the
configuration file.

The system theme was named Default even though the default theme is Dark.
This addresses that by renaming Default.qss to System.qss. I've made it
backwards compatible so users already using this theme are not affected.

The theme list now shows up as:
-System
-Dark (Default)
-Acri
-Rachni

I have also made it so that you can specify the default theme in the
UI config file.

This fixes a seg fault that would happen when launching OBS from the
terminal and then hitting ctrl-c.

Allows the ability to use invokeMethod on the OBSApp object to execute
an std::function.  This allows deferring an std::function call to the Qt
event queue.

Instead of relying on the default config values (which can change
depending on language), explicitly set the values when run for the first
time.

If the user doesn't use the auto-configuration on first use, set the
default encoders used in simple output mode to hardware encoders.

Closes obsproject/obs-studio#1602

Although log files are saved with the date in the name of the log file,
it's also nice to be able to see it inside the log file itself,
especially when uploaded to a text service.

OBS Studio currently does not support retina rendering for any of the
images in the app. This adds support for retina pixmap rendering as
well as adding higher resolution versions of each icon that was not
a high enough resolution to support 2x. The icons work when switching
themes and will only render the 2x versions when the device pixel
ratio is greater than or equal to 2.

I also added credits to the readme for images that were already being
used that require credit to the author. If the OBS community has
paid for these images already, I can remove the credits from the
readme. The credit is for the invisible, visible, and gear icons.

Due to reports of issues with Windows 7, if the user is on windows
version 7 or below, set the default for "Browser Source Hardware
Acceleration" to false instead of true.  This ensures optimal user
experience and still allows those who had it working to continue using
it if they so choose.

Exact cause for this issue on Windows 7 is currently unknown.

Adds a checkbox to advanced settings that allows the user to
enable/disable browser source hardware acceleration on windows.

Changes the default "preferred" GPU to the NVIDIA GPU when running the
program on NVIDIA laptops.

This commit explicitly puts "32-bit" in the title bar and OBS log for
32-bit versions of OBS. It also changes "64bit" to "64-bit" to match the
string used for Windows version info.