ide: remove not sexy bevels from the dialog

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41714 4005530d-fff6-0310-9dd1-cebe43e6787f
ide: remove toolbar top bevel from the Additions and Overrides frame. We don't use Top Bevel for other IDE toolbars and bottom bevel is not needed too since bottom control has it own

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41715 4005530d-fff6-0310-9dd1-cebe43e6787f