EDU-177 Delete error highlighting for custom nodes in project view
Merge remote-tracking branch 'origin/master'
cleanup — introduce var to avoid synchronized getter
use app.getConfigPath() instead of PathManager.getConfigPath() (otherwise it is impossible to test, CR-IC-6201)

move "refresh config dir VFS" from FileBasedStorage to ApplicationStoreImpl — FileBasedStorage used not only for app config, so, it is not his business to do it
override
test groups: merge groups from different testGroups.properties files