Add button to clear Renderer cache
Add a listener that clear the cache and redraw when a showned table has been modified
Remove useless call to repaint()
Merge pull request #705 from nicolas-f/fix/mapcontrol_cache

Mapcontrol cache

Add a button in map editor to clear the data cache and redraw the map.
Add a listener on table in order to clear the map editor data cache when the table is edited.