IDE: mode matrix: highlight error values

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41267 4005530d-fff6-0310-9dd1-cebe43e6787f
IDE: allow to uninstall dummy packages

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41268 4005530d-fff6-0310-9dd1-cebe43e6787f