More complete handling of printf formatting in msgid/msgstr checks.

(That commit, r60813, should never have been done to 2.69 branch, will revert it there, sorry :/ ).

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@60860 954f8c5b-7b00-dc11-b283-0030488c597c