- Update graphics/png to 1.6.16
- Patch oolite to build with this new version
A portrevision bump will follow soon

Differential Revision:	https://reviews.freebsd.org/D1360
Submitted by:	bapt
Exp-run:	self
Bump portrevision after png update
Bump portrevision after png update
Mark as broken after png update
Mark as broken after png update
Remove USE_GCC added by mistake
Add webkit2-gtk3 2.6.4.

This port only supplies the WebKit2 library for gtk3, and has some API changes.
The webkitgtk project switch to cmake. Due to issues I don't understand
  yet we can't use USES=cmake yet.
Use USES=compiler:c++11-lib to replace custom dancing around with clang
  and OSVERSION.
Make 8.x as IGNORE, because of c++ and other issues.
revert changes not ready to get in
Update to 0.5