Fixed compilation issues and improved performance on OSX.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4606 dfc29bdd-3216-0410-991c-e03cc46cb475
Updated changes.txt file.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4607 dfc29bdd-3216-0410-991c-e03cc46cb475