IDE: clean up package dependencies dialog: remove selected dependencies

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40768 4005530d-fff6-0310-9dd1-cebe43e6787f
cody: clean up

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40769 4005530d-fff6-0310-9dd1-cebe43e6787f