yet another fix..
removed unnecessary code
removed debug code
surface.DrawNinePatch: fixed issue with top middle rect not being correct
added a way to make the divider invisible but still draggable
added some functions to control the style in press and unpressed states
added Set/GetClicksToActivate for double clicking and such
added center_x and center_y to dock function
added functions to copy specific panel sizes
fixed some layout issues with stacking
code cleanup
more work on properties
defined more styles