Show GUI feedback to the user if FFmpeg.exe path does not exist
Skip regserver if not run as admin
AboutForm tab index fixes
Only show message box when FFmpeg download fails
Added libvo_aacenc support
FFmpeg options form changes
Updated FFmpeg tooltip
Merge branch 'master' of https://github.com/ShareX/ShareX

Conflicts:
	ScreenCaptureLib/Screencast/FFmpegOptionsForm.Designer.cs
Revert "Updated FFmpeg tooltip"

This reverts commit 248fa9b7231bbbfc3bcf5ef97c50c1f2a9102fd8.
FFmpeg options form changes
fixed screen record canceling
Change default FFmpeg audio codec to libvo-aacenc

After running more tests, AAC volume was not that low compared to
Vorbis:

https://dl.dropboxusercontent.com/u/84476328/ShareX/2014-05/2014-05-15_05-10-26.mp4

https://dl.dropboxusercontent.com/u/84476328/ShareX/2014-05/2014-05-15_05-10-03.mp4

https://dl.dropboxusercontent.com/u/84476328/ShareX/2014-05/2014-05-15_05-09-35.mp4
Remember custom extension for FFmpeg set by user
Revert "Remember custom extension for FFmpeg set by user"

This reverts commit da43af6346f86d4c80bf5760d17f20871190f42e.
Support for mkv extension in FFmpeg
Refraining usage of hardcoded strings for easier coding
Cancelling Before Upload form will not show an Error icon in the main form anymore
Fixed ffmpeg extensions
TabIndex changes
More TabIndex fixes