[espresso/f19] (2 commits) ...mpich no longer use mpd, therefore pwgen is no longer required

[Deji Akingunola]

Summary of changes:

  a46525b... Rename mpich2 sub-packages to mpich and rebuild for mpich-3 (*)
  d95cf8d... mpich no longer use mpd, therefore pwgen is no longer requi (*)

(*) This commit already existed in another branch; no separate mail sent