Merge branch 'maint' into branch-1.11

Merge branch 'maint' into branch-1.11

* maint:
  info: allow user to inhibit creation/update of '${infodir}/dir'
  dejagnu: allow the package developer to extend site.exp
  * THANKS: Fix whitespace issue.
  deps: partially revert commit `v1.11-512-geeee551'
  dejagnu: ensure 'srcdir' is defined as a relative directory
  Fix testsuite failure of check12.test without DejaGNU.
  Extend and improve tests on DejaGnu support.