Some refactorings of the patch header code.
Part of a stalled attempt to fix issue2445, but worthwhile in itself.
3 patches for repository darcs-unstable@darcs.net:screened:
Sat Mar 21 10:01:53 GMT 2015 Ganesh Sittampalam <ganesh@earth.li>
* extract updatePatchHeader into a separate module
Sat Mar 21 10:45:57 GMT 2015 Ganesh Sittampalam <ganesh@earth.li>
* move getLog into Darcs.UI.PatchHeader
Sat Mar 21 10:52:55 GMT 2015 Ganesh Sittampalam <ganesh@earth.li>
* refactor updatePatchHeader a bit
It only needs a repository when asking about dependencies