Fix another KTE::Range/Cursor porting bug.
Update plugin description and setup dependencies.
Guard against crashes
Cleanup code and delay initialization of internal PHP file.

The internal PHP function file will now be initialized on the first
parse job run of any other PHP file.

The PHP documentation and unit provider plugins are still triggering
parse jobs of this internal file though...
Fixup installation of unit provider plugin
Mark the unit provider plugin as GUI.

It's not interesting for non-gui use-cases imo. And it reduces
the amount of unit tests this interacts with by getting loaded
automatically.
Added a const& in the ParseJob class.
duchain/tests: pick the proper path for the internal functions file.
CMake: 'kdev4' -> 'kdev' for target names