It should be possible to enter styles into the sytleClass, the columnClasses, rowClasses, etc. with the names of style
class that do not yet exist.  In fact, it would be real nice to be able to just type in style class names and while the
IDE can give the hint that the style class does not exist, it should still allow it.

While developing and application it is really a pain to realize that you need a style class, have to suspend work on the
page, open the style sheet up, add a new style class, go back to the IDE, chose the [...] find the style class in the
popup (and sometimes it does not show up unless you "Refresh" the page), and pick the style class.  

Why not just let the user type in the style class and maybe give a warning that the style class does not exist but allow
it to be entered anyways.