Fix issue #126 with Leiningen 2.5.0 due to auto-cleaning of targets
Fixing issue #126 with Leiningen 2.5.0 due to auto-cleaning of targets
being the default behaviour and thus wiping the auto-compiled main class
before packing

Updated code for avoiding auto-clean in Leiningen 2.5, conforming it to
the preferred way of handling project modification.

Falling back to having no-uberjar-clean as a private function of
leiningen.rung.uberjar.

Fix formatting and using vary-meta instead of with-meta