Codetools: a temporary fix for commenting out the whole uses section in implementation part.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42458 4005530d-fff6-0310-9dd1-cebe43e6787f
Converter: improve the GUI for commenting / skipping missing units.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42459 4005530d-fff6-0310-9dd1-cebe43e6787f