[gdm] (5 commits) ...Merge branch 'wip/foreach-fixes' into 'master'

[Ray Strode <halfline src gnome org>]

Summary of changes:

  47d01ab... display-store: make foreach ignore callback return value (*)
  c9e0237... xdmcp-display-factory: don't return value from foreach func (*)
  c9214f0... local-display-factory: don't return value from foreach func (*)
  a964604... manager: don't return value from listify_display_ids (*)
  00040c5... Merge branch 'wip/foreach-fixes' into 'master'

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