In other words, a pilot can only be used in the same language it was
created with. Checks both the initial selection screen and in the
barracks.
Also fixes issue with PLR version being ignored in pilotfile::verify()
git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10817 387891d4-d844-0410-90c0-e4c51a9137d3