Revert "changed rectangles client side implementation...

...to be only a "marker" for draw stuff" and extended RectangleTest.

This reverts commit a7640fea97db65a4a0319cfb044c8cea471bfb6d.

This is for issue #67. Restoring the RectangleState and the full implementation of the LeafletRectangleConnector (that instantiates a Rectangle) makes the rectangle correctly editable.

I do not know if there is a better solution.

I have extended the RectangleTest to activate draw.