[glib] (3 commits) Non-fast-forward update to branch wip/pwithnall/credentials-fix

[Philip Withnall <pwithnall src gnome org>]

The branch 'wip/pwithnall/credentials-fix' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  acbaae6... gcredentials: Add missing header needed for glib_typeof

Commits added to the branch:

  1655dc9... Revert "Use C++11 decltype where possible" (*)
  b67185c... Merge branch 'revert-decltype-changes' into 'master' (*)
  0f18064... gcredentials: Add missing header needed for glib_typeof

(*) This commit already existed in another branch; no separate mail sent