[tcsh/f18] (4 commits) ...Update to tcsh-6.18.01

[Fridolín Pokorný]

Summary of changes:

  a21398b... Fix tcsh being interruptible while waiting for child proces (*)
  f379b93... - Rebuilt for https://fedoraproject.org/wiki/Fedora_19_Mass (*)
  bed5d53... Fix history problems (#879371 and #919452), histlist length (*)
  fbd41bb... Update to tcsh-6.18.01 (*)

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