[geary] (10 commits) Non-fast-forward update to branch mjog/692-dont-serialise-empty-array

[Michael Gratton <mjog src gnome org>]

The branch 'mjog/692-dont-serialise-empty-array' 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:

  97530fa... Geary.Imap.Serializer: Don't try to serialise empty literal

Commits added to the branch:

  3202a9c... Application.FolderStoreFactory: Fix critical on account rem (*)
  f0c1dfe... Application: Make Plugin.EmailStore impl usable by other cx (*)
  45d05dd... Plugin: Fix some bad API docs (*)
  1beea00... Application: Minor API doc comment update (*)
  2e623a5... Geary.Smtp.ClientService: Pass a Geary.Email to sent-mail s (*)
  e7c7326... Plugin.EmailStore: Actually emit the email-sent signal (*)
  a47e0fc... Plugin: Add new sent-sound plugin (*)
  2f3f2ca... Merge branch 'mjog/598-sent-email-sound' into 'mainline' (*)
  652f77f... FolderList.Tree: Fix search folder not appearing when selec (*)
  2826bf0... Geary.Imap.Serializer: Don't try to serialise empty literal

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