Make the request processor clear empty variables from the methodURL, add support for optional blocks in methodURL

*	Now the :var_name pieces are taken out of the URL if the user leaves them blank.
*	Now you can add blocks around optional portions of a methodURL, like this: "/path[/:optional]/more" and if :optional is blank, the methodURL will render as "/path/more" instead of "/path//more" if this support were not enabled. The display of the brackets to the user also naturally shows them how to build the path themselves.