WebKitGTK 2.49.1 released!

This is the first development release leading toward 2.50 series.

Change threaded rendering implementation to use Skia API instead of WebCore display list that is not thread safe. This also allowed to improve performance by recording layers once and replaying every dirty region in different worker threads.
Added hybrid rendering mode that tries to use the GPU worker threads, but if they are all busy the CPU worker threads are used if possible.
Add volume locking support to media player.
Add support for tracing counters with Sysprof.
Fix several crashes and rendering issues.

Thanks to all the contributors who made possible this release.