Remove redundant ReadOnly() method
Extract paint functionality to bypass FPS throttler

The FPS throttler ignores repaints when they happen too frequently. If
the repaint being ignored happened to be requested in response to a
resizing event it would have undesired effects on how views allocate new
subviews and dispose of old ones.

Repaints triggered by resizing are now forced to be executed by directly
calling paintForced() and therefore bypassing the FPS throttler.