Support profile target-paths

Fixes case where running

        lein with-profile build bin

fails because the profile is appended to the project's :target-path.

leiningen.uberjar/uberjar returns the jar path as of this commit on
2011 June 22:

https://github.com/technomancy/leiningen/commit/a03507660dc9caceb57face928f7c62981b66295
Merge pull request #15 from guns/profile-target-paths

Support profile target-paths