added ofxAudioUnitGetParametersExtra methods

method to get non-Apple AU's list of parameters and properties
move param utils to ofxAudioUnit base class
(also add explanation to params example)
temporarily remove external au params example
add CAPublicUtility files to examples
make sure UI windows are created on the main queue
add thumnail
initial pause resume, resume time is off
working pause / resume
Closes #8
fix recently broken getLength() in file player
prime file player before playing
Closes #5
expose prime() as a public function for file player
handle case where play() / pause() calls are unbalanced
add playAtSampleTime() to ofxAudioUnitFilePlayer
(allows playback starting at an arbitrary point in the file)
make stop() reset the pause playhead in file player
Merge pull request #10 from admsyn/fileplayer-pause-resume

ofxAudioUnitFilePlayer pause / resume, priming, seeking
allow DSP nodes to be connected to each other
closes #9
properly set source busses for DSP nodes
add ofxAudioUnitRecorder