[CHG] doxygen files updated to 1.8.6

git-svn-id: http://grrlib.googlecode.com/svn/trunk@466 eccdf170-e2e9-11dd-a8eb-ddf07f3c1838
[CHG] libpng updated to version 1.6.8
[CHG] zlib updated to version 1.2.8

git-svn-id: http://grrlib.googlecode.com/svn/trunk@467 eccdf170-e2e9-11dd-a8eb-ddf07f3c1838
[CHG] Copyright dates changed to 2014

git-svn-id: http://grrlib.googlecode.com/svn/trunk@468 eccdf170-e2e9-11dd-a8eb-ddf07f3c1838