[geary] (44 commits) ...Merge branch 'mjog/email-templates' into 'mainline'

[Michael Gratton <mjog src gnome org>]

Summary of changes:

  8b3e01f... Application: Rename plugin context objects to make their us (*)
  9952143... Application.AccountContext: Break out unto standalone sourc (*)
  c4b44b4... Application.FolderContext: New class for aggregating client (*)
  1a34568... Sidebar.Entry: Coalesce multiple entry changed signals into (*)
  3ffa6e1... FolderList.FolderEntry: Emit `::entry_changed` on folder co (*)
  778cb2d... Application.AccountContext: Add signals for folder context  (*)
  60f3fac... Application: Pass Controller instance to to plugin objects  (*)
  e9ce94b... Application.FolderStoreFactory: Convert to using app & fold (*)
  e22d74d... Geary.Folder: Add `SpecialUse.CUSTOM` and `set_used_as_cust (*)
  9345323... Plugin.Error: Add NOT_SUPPORTED type (*)
  1dfd5a1... Plugin.FolderPluginContext: Support registering special use (*)
  5f2d40b... Plugin: Add new Composer object and Application.new_compose (*)
  5a94d4b... Application.PluginManager: Move plugin account mgmt from fo (*)
  c719c70... Plugin.EmailIdentifier: Add `account` property (*)
  624b9ab... Minor doc comment updates (*)
  5519ba8... Application.PluginManager: Use AccountContext keys for acco (*)
  2f66621... Application.FolderStoreFactory, EmailStorefactory: Remove c (*)
  97b807f... Application.FolderStoreFactory: Improve folder signal impl (*)
  aff5998... Plugin.EmailStore: Add methods for getting email ids from v (*)
  0b0efd0... Application.FolderStoreFactory: Move get_folder_from_varian (*)
  a98f953... Application.Client: Use plugin variant formats for app acti (*)
  aac59ec... Application.Controller, Composer.Widget: Clean up composer  (*)
  96ddd5a... ConversationListBox: Remove obsolete action and signal (*)
  fc4bc92... Composer.Widget: Convert to using AccountContext objects (*)
  6a33266... Composer.Widget: Re-load a context email with missing field (*)
  a67f1b2... Application.{Controller,MainWindow}: Clean up displaying co (*)
  480277e... Application.MainWindow: Email not found error when discardi (*)
  2cd43de... ConversationViewer: Avoid re-enabling kinetic scrolling if  (*)
  6fd3f36... Plugin.Composer: Add support for editing an email in the co (*)
  924231d... Plugins.SpecialFolders: Actually implement the edit draft a (*)
  085ed9a... Geary.App.DraftManaager: Update API to something more RAII- (*)
  14f3dd0... Application.Controller: Allow creating composers with alt s (*)
  4f92c2b... Plugin.InfoBar: Allow secondary buttons to be specified. (*)
  33a6134... Plugin.Composer: Support specifying a folder to save email (*)
  1051072... Plugin.Composer: Support disabling sending a composer (*)
  47d4056... Plugins: Add EmailTemplate plugin (*)
  9a2fe63... Application.Controller: Ensure outboxes appear in the folde (*)
  400850c... Geary.AccountInformation: Rework how special use folder pat (*)
  e0dc785... Geary.ImapEngine: Don't add local folders then update their (*)
  48ed8d9... Geary.Account: Support creating folders in the personal nam (*)
  13e339f... Plugin.Account: Support creating folders in the personal na (*)
  1b529d2... Minor doc comment update (*)
  1986633... Plugin.EmailTemplate: Create templates folder if it does no (*)
  9e0ae0e... Merge branch 'mjog/email-templates' into 'mainline'

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