[geary] (10 commits) ...Merge branch 'wip/improve-claiming-folder-session' into 'master'

[Michael Gratton <mjog src gnome org>]

Summary of changes:

  8d1b5b5... Add Geary.Account.is_online property (*)
  69ac6eb... Remove Geary.Folder.wait_for_remote_async() (*)
  7b4f30c... Tidy up ReplayOperation API (*)
  ecda651... Don't actually execue remote ReplayQueue.CloseReplayQueue o (*)
  ab66ef9... Ensure IMAP client session is released on error claiming fo (*)
  a6e0fe9... Add a nonblocking queue peek() method (*)
  e470cd7... Ensure account sync waits for remote to open before procedi (*)
  2802303... Ensure the IMAP pool is stopped on connection error (*)
  3487a29... Cancel any pending commands when ImapClientConnection disco (*)
  2573456... Merge branch 'wip/improve-claiming-folder-session' into 'ma

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