liblangtag: update to 0.6.7.

0.6.6 -> 0.6.7
=================
Akira TAGOH (1):
      Add missing header

0.6.5 -> 0.6.6
=================
Akira TAGOH (2):
      Do not use variable array of bash-ism.
      Fix more compile warnings

0.6.4 -> 0.6.5
=================
Akira TAGOH (6):
      Fix the test case
      Add missing headers
      Drop GNOME-related macros
      Fix some compiler warnings
      Merged in issues/18 (pull request #11)
      Update

(wiz)