Adds support for pausing recordings.  When settings are eligible for
recordings, a pause button will appear next to the recording button.  If
the settings are not eligible, it will warn the user in the output
settings that they cannot pause recordings if those settings are used.

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.

All UI elements are accessible through the obs frontend api via
obs_frontend_api_get_main_window, except for the tray icon and its
elements. This commit adds an obs_frontend_api_get_system_tray function
which returns the pointer to the QSystemTrayIcon cast to void (much like
the QMainWindow pointer for the main window).

Allows the ability to add a new scene collection via the frontend API.
Blocks until the scene collection has been successfully added to ensure
synchronization between the calling thread and the UI thread.

(Jim: Added detailed description to commit message)

Closes obsproject/obs-studio#1232

Allows the ability to perform multiple actions that would normally save,
and defer the save until all of those actions are complete.

Closes obsproject/obs-studio#1231

Closes jp9000/obs-studio#1106

Prevents SWIG from being able to process certain declarations that would
cause binding generation errors/warnings.

This event is called when all scene data has been unloaded.

Allows loading data before actually loading any scene data.

With these new functions, plugin developers can enable, disable and
get the status of Studio Mode, as well as get and set the current
preview scene and transition the current preview to Program

Here is a list of the Studio Mode events:
   - Studio Mode enabled
   - Studio Mode disabled
   - Previewed scene in Studio Mode changed

This commit adds functions to get, set and save the service and its
settings, and is plugged straight into the existing internal functions
serving this purpose

(Jim: Fixed commit message and missing newline at end of file)

Closes jp9000/obs-studio#895

Replay buffer and recording should be separate in case the user wants to
start recording from a specific point rather being forced to reconfigure
for regular recording.

Creates a new button on the main window below the recording button for
turning on/off the replay buffer.

Allows manipulating and modifying the front-end via plugins.