Minor documentation tweak and if an incorrect parameter is given to core show...

Minor documentation tweak and if an incorrect parameter is given to core show translation return the usage information.
(closes issue #11316)
Reported by: eliel
Patches:
      translate.c.patch uploaded by eliel (license 64)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89449 65c4cc65-6c06-0410-ace0-fbb531ad65f3