Remove the uber template

This has been moved to playdoh itself

 - added --dirname feature
 - refactored the Template and entry point

cc @sh1mmer @kumikoda
I guess my point is: why not leave `uber-ngen` as-is and fold it into `playdoh` proper? I know you like to slice and dice code into the smallest modules possible, but rather than keep the artificial playdoh/uber-ngen separation, if you fold it in, simplify it, and break it back apart, you'll probably have a better fit for what's needed.