[plugin] Re-enabled part of YouCompleteMe config

Re-enabled:
- No diagnostic signs
- No confirmation for extra config (.ycm_extra_conf.py)

Change-Id: I6ee8f50728c0517813fb20c5865f3e074ddfa722
Merge branch 'cleanup' of ssh://github.com/rafaelnp/rnpvim into cleanup

* 'cleanup' of ssh://github.com/rafaelnp/rnpvim:
  plugin: Disabled diagnostic signs in ycm
  [aucmd] Re-enable youcompleteme custom C/C++ flags file

mit '#' werden ignoriert, und eine leere Beschreibung

Change-Id: Iff01b979fa267c7d497d65736649cddc0a87f348