remove clean targets for all profiles

Fixes issue #1721 

For `lein clean`, in addition to deleting all of the clean targets for the project, generate profile-specific clean targets for all known profiles and (attempt to) delete all of them as well.

(all tests pass)
Moved the call to jar/get-jar-filename *after* jar/jar, so that the path it creates is not cleaned up by jar/jar. This matters for profile-specific target paths.