win32: set control text for TBitButton also although it does not draw it natively (issue #0024135)

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41655 4005530d-fff6-0310-9dd1-cebe43e6787f
synedit: clean up

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41656 4005530d-fff6-0310-9dd1-cebe43e6787f