AERecorder: separate startRecording method
Minor TPCircularBuffer update

- Added a couple of extra sanity checks for ABL utilities
- Use const keyword for AudioStreamBasicDescription parameters
Added missing 4096 kAudioUnitProperty_MaximumFramesPerSlice assignment for main output unit
Switched order of audio unit setup calls for AEAudioUnitFilter/Channel

See http://forum.theamazingaudioengine.com/discussion/104/aeaudiounitfilter-couldnt-setup-converter-audio-unit-error/p1 for discussion
Merge pull request #45 from lijon/aerecorder_separate_prepare_and_start

AERecorder: separate startRecording method
Adjusted AERecorder workflow
Updated podspec
Merge branch 'official_master'

Conflicts:
	Modules/AERecorder.h
	Modules/AERecorder.m