Move imports into header

--HG--
extra : amend_source : 371b48777dba5d8a4d62b5899944471752f830bd
extra : histedit_source : 0739a1da7f11a5f6e348a34b203a9328d0bc0f22
Remove commented code

--HG--
extra : histedit_source : 7600ecd3914abc4767d4296f62b038a6397df673
Avoid trailing comments in pkg_resources.

--HG--
extra : histedit_source : fba32276bb6acd7b5e44ff596407d10c94c618a9
Normalize whitespace per more modern style conventions.