OBS Multiplatform 0.12.1

Changes:
* Added an option to the source creation dialog to set a newly created source's initial visibility
* Added a "pixel format" option to the Decklink source
* Image sources will now check for file changes and automatically reload their files if the file is changed
* Greatly improved startup time
* The program now only disables sleep/screensaving when streaming/recording is active, or when a fullscreen projector is open
* Changed the "center source" shortcut from Ctrl-C to Ctrl-D (Ctrl-C is used for clipboard copy)
* Fixed various bugs with the freetype2 text source where the text could show up as garbled or not display
* Fixed an issue loading text files for freetype2 that contained non-english characters
* Fixed an issue where the program could freeze for very long periods of time when disconnecting or reconnecting under certain circumstances
* Fixed an issue where reconnections could send out erroneous initial packets
* Fixed an issue where where the program could experience unjustified disconnections after a specific period of time
* Fixed an issue where under certain circumstances the connection would not be closed on disconnection
* Fixed a bug that would prevent the ability to select more than once source at a time

Mac:
* Added a number of options to the video device source (when presets are turned off), such as options to set a specific custom resolution/framerate

Windows:
* Fixed an issue with the input audio capture which would causse mics to sometimes have strange sync issues
* Fixed a performance issue with D3D9 games on the new windows 10 update
