Merged libpng 1.6.2 from vendor branch. Updated pnglibconf.h to latest predefined config file to catch up with latest setup requirements.
Merged version 9 of libjpeg from vendor branch.
Merge from vendor branch version 1.2.8 of zlib
git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/branches/ogl-es@4638 dfc29bdd-3216-0410-991c-e03cc46cb475