Try to fix #4889 in the right way

Try to fix #4889 in the right way

For reference, the bug was that quote insets grew bolder because, when
painted over themselves, anti-aliasing made them darker.

It turned out that the fix there created others than were
painstakingly fixed: #7164, #7165, #7174, #7193... More recently, it
created other problems:
http://article.gmane.org/gmane.editors.lyx.devel/163471

We use the right fix here:
* draw background of quote inset when not doing full repaint
* draw background of math macro template when not doing full repaint
* remove hack that grew from #4889 fix.