Improved graphics capture hooking
Preserve current capture target selection if it isn't running
Fix crash in Settings window if no audio devices present
Fix crash when removing a global source with no scenes
Fix a derp
Extract out file naming and file stream creation from OBS::StartRecording
Add IntervalFileOutput

Buffers at least the configured amount of seconds of video and audio
packets and writes them to a new file when SaveInterval is called
Streamline (settings) hotkey handling

This moves all hotkeys that were accessible in the audio/publish
settings panes to a new hotkeys settings pane

Also makes the push to talk hotkeys behave like all other (settings)
hotkeys, i.e. as long as a hotkey is configured the hotkey is active
Add Save Interval support to UI/recording logic
Save complete segments
Don't start the replay buffer if we're not recording
Replace save interval with replay buffer and add recording button label
Fix minor problems
Show estimated memory usage