Update Readme.md

Update OS X requirement to 10.9 as per https://code.google.com/p/dolphin-emu/issues/detail?id=7243
Update CMakeLists.txt
Fix name conflict between SoundTouch BOOL and ObjC BOOL.
Switch from deprecated Carbon idle tickling to Cocoa power assertions.

Also, this avoids keeping the system awake if a game is not being
played.

Frankly, I don't know what the point of precisely tracking these things
is, but that's how the API works.  Feel free to add analogous
functionality on other platforms.
Update Main.cpp version checks.
Upgrade AudioUnit API usage.

weird that such a simple change doesn't seem to have any obvious
documentation on Apple's website or elsewhere...
Merge pull request #1561 from comex/10.9

Update OS X Requirement to 10.9 + fixes