Added a delegate which is called before the audiovideorecorder does the mix between the audio file and the video file. It allows the user to modify the recorded file before creating the mix.
Exposed the currentRecordingTime in the XamarinBindings
Removed startRunningSession and stopRunningSession in notifications.
Enabled the aspect fill scaling in the asset writer. You can now set a
different aspect ratio in the videoEncoder.
Merge branch 'master' of github.com:rFlex/SCAudioVideoRecorder