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)
Closesjp9000/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.
