WebKitGTK+ 2.13.3 released!

This is a development release leading toward 2.14 series.

Fix Web Process deadlocks when loading HLS videos.
Make videos work when painted into a canvas when accelerated compositing is enabled.
Fix flickering with animated GIFs.
Fix a Web Process crash when video repaint is requested with GStreamer GL enabled.
Reduce the amount of file descriptors that the Web Process keeps open.
Make memory pressure handler work when cgroups are not available.
Fix several crashes and rendering issues.

Thanks to all the contributors who made possible this release.