Fixed method parameters of dumb method

//cc @craigh
Fixed route creation - even the page dummy parameter must be numeric.
unset helper variables.
create interface and abstract class. make ModUrl extend same.
update `RouteUrl::getUrl()`
correct fragment addition. update docblocks
combine ideas and provide BC by extending `ModUrl` instead of `AbstractUrl`
refactor to remove AbstractUrl. It was a redundant class. This moves all implementation to the Child classes which is more proper IMO.
change order of methods to align with old file.