use xxhash to generate material id
add xxhash on linux
use xxhash in win32 and wp8
Merge pull request #15 from koowolf/quadcommand-optimize

use xxhash in win32 and wp8
use xxhash in win32 and wp8
Merge branch 'quadcommand-optimize' of https://github.com/minggo/cocos2d-x into quadcommand-optimize

Conflicts:
	cocos/2d/cocos2d_wp8.vcxproj
	cocos/2d/cocos2d_wp8.vcxproj.filters
Merge pull request #16 from koowolf/quadcommand-optimize

use xxhash in win32 and wp8
Merge pull request #6066 from minggo/quadcommand-optimize

use xxhash to generate material id