LCL: set Application to nil on free

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45297 4005530d-fff6-0310-9dd1-cebe43e6787f
lazbuild: keep Application, needed for processmessages

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45298 4005530d-fff6-0310-9dd1-cebe43e6787f