cmake support for window

Quickly added cmake support for windows because I was bored.

Tested on Visual Studio 2013

Instructions 

1. Open cmd prompt in cocos2d/build folder
2. mkdir win32 and then cd into win32
3. cmake -G"Visual Studio 12" ../../

Should work with Visual Studio 11 (ie. 2012)
and Visual Studio 10 (ie. 2010)

I might have broke Linux in the Process.
but I'll add it back in with Mac Ios and Android at some point.

Have fun

Martell