cleaning up the logic in the process. Should now be easy to move to a
controller-view split.
Moved the minw_, minh_ bug-fix into the base class. Can now forget about it!
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@1793 a592a061-630c-0410-9148-cb99ea01b6c8