tried doing this smarter by validating the property exists in UI code before access but this ended up making it too complicated and also hard to account for possible access without checking every time.
for now just redraw all areas when a user property is changed.
ui/ --> startup/bl_ui
op/ --> startup/bl_operators
scripts/startup/ is now the only auto-loading script dir which gives some speedup for blender loading too.
~/.blender/2.56/scripts/startup works for auto-loading scripts too.
