Log Message:
Update to kdevelop 4.6.0

Aside from many bug fixes and general improvements such as performance
optimizations in various areas, which make KDevelop 4.6.0 faster and less
memory-hungry, a few changes are especially noteworthy:

The ReviewBoard plugin now supports updating existing review requests.
There is a new plugin which adds support for building projects with ninja
instead of make. CMake support was also stabilized and improved, adding
support for missing or new CMake features.