* The layout friendly constructors don't need to mess with the control size.
* The layout friendly constructors can use the respective BControl constructor.
* Refactored some duplicated code.
* Removed duplicated GetFontHeight() calls.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27585 a95241bf-73f2-0310-859d-f6bbb57e9c96