[Stk] STK Repository structure

[Ariel Elkin]

Great to see the STK git repository is coming along!

I think that something that would really improve the STK's support for iOS, AND make it easier to create ports for other platforms, is if we clearly separate the STK's audio classes from the STK's helper classes. Classes solely dedicated to audio purposes (e.g. Sitar, PRCRev, etc.) should be grouped in their directory. The STK's helper classes, such as those for networking (e.g. Socket, TcpClient) multithreading (e.g. Mutex), or audio layer setup (e.g. RtAudio), should be in separate directories.

I thought about this directory structure:

STK/Classes			<-- All the audio classes, both .h and .cpp (e.g. Guitar, Mandolin, Twang)
STK/Rawwaves		<-- All the raw waves
Utilities/Networking	<-- All the networking classes
Utilities/IO			<-- All the file I/O classes (e.g. RtAudio)
Utilities/Multithreading
Demo/OSX
Demo/Windows
Demo/iOS

Let me know if you have comments or suggestions! 

Ariel