servo / libpng

[libpng16] Imported from libpng-1.6.3beta04.tar

[libpng15] Imported from libpng-1.5.16beta04.tar

[libpng17] Imported from libpng-1.7.0beta12.tar

[libpng16] Imported from libpng-1.6.3beta03.tar

[libpng17] Imported from libpng-1.7.0beta11.tar

[libpng16] Imported from libpng-1.6.3beta02.tar

[libpng16] Bump version to 1.6.3beta02

[libpng15] Imported from libpng-1.5.16beta03.tar

[libpng15] Imported from libpng-1.5.16beta02.tar

[libpng15] Bump version to libpng-1.5.16beta02