Merge pull request #2 from damonconway/master

Worked on mkMhiLinks
Simplify mkMhiLinks:
  * cp takes multiple src args
  * don't cp then sed then mv; just src -> sed -> dest
  * simplify mkdestdir logic to not repeat itself
convert _argFolder to an @takesFolderArg decorator
Make a connection manager to auto close/logout
refactor out _cur_msg(folder)
factor a join into _fixupMsgset and rename it