[glibmm] (3 commits) Non-fast-forward update to branch wip/dboles/SettingsSchemaSource-Issue#19

[Daniel Boles <dboles src gnome org>]

The branch 'wip/dboles/SettingsSchemaSource-Issue#19' 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:

  577a976... SettingsSchemaSource: Implement list_schemas()
  8699808... SettingsSchemaSource: Wrap new_from_directory()

Commits added to the branch:

  c5bbd26... Glib::Binding: Explain why SlotTransform takes GValue* (*)
  875dacf... SettingsSchemaSource: Implement list_schemas()
  7c943fa... SettingsSchemaSource: Wrap new_from_directory()

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