[FIX] Fixing several paths for the core/extras level removal.
[FIX] Removing some problems introduced by the core/extras merging.
[FIX] Fixing yet another search-and-replace bug.
[FIX] Yet another path fix for core/extras merge.
Merge pull request #718 from holtgrewe/feature/fix_paths

Fixing some more problems related to removing core/extras