Fix pack and unpack include file to properly work under MSVC as well. Needs to suppress warning as we don't have the push and pop together anymore.
Fix push and pop usage - some files forgot to add the define, so effectively not work under gcc with special architectures - and move all files to use the new include files.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4196 dfc29bdd-3216-0410-991c-e03cc46cb475