Update `collapse-fn` tests to illustrate argument order

Didn't like having a property that was so crucial ingored in the tests
Skip anaemic helper
Whitespace and test group merge
Implement artifact/group-id editability
Fixup regular expression to be less lenient
Reappropriate `bump-version` function for `lein.change` usability

One wart to notice is that argument order is switched between
`bump-version-map` and `bump-version`. This is because the `lein.change`
semantics enforce that version-string is the first argument.

Have not added tests for this function, do you think we should?
Update `leiningen.change` tests to use real `bump-version`

Not sure what you think of creating this kind of coupling in the tests.

This were useful tests for driving the previous commits, but happy to
delete them now.
Fix things broken by late rename

Note to self:

Always unload namespaces and test again after renaming.
Merge remote-tracking branch 'crisptrutski/lein-release-and-change-interop'

Conflicts:
	src/leiningen/release.clj
	test/leiningen/test/release.clj
Merge remote-tracking branch 'crisptrutski/set-group-or-artifact-id'

Conflicts:
	src/leiningen/change.clj
Merge remote-tracking branch 'upstream/master'