build error fix for the tests.
Merge pull request #344 from oxosi/test

build error fix for the tests.
use Array.Sort for sorting children
Merge branch 'master' of https://github.com/Cocos2DXNA/cocos2d-xna
not clean OrderOfArrival
Merge pull request #345 from gena-m/master

use Array.Sort for sorting children
fixed sprite tests
Merge pull request #346 from gena-m/master

fixed sprite tests
Fix for the winrt/windows8 builds that do not have Thread support.
Fix Remove child to not exception out if the child to remove is passed as null.