[geary] (14 commits) Created branch mjog/mutiple-main-windows

[Michael Gratton <mjog src gnome org>]

The branch 'mjog/mutiple-main-windows' was created.

Summary of new commits:

  419bc6d... Remove GearyApplication.instance global var
  5687636... Rename GearyApplication class and source to match code styl
  239fdce... Move MainWindow to Application package
  0dce504... Promote AccountContext to a top-level internal class
  e2a3902... Drop Application.Controller access to internal
  ab8755a... Add Application.Controller::account_available and unavailab
  3ca121f... Move Application.MainWindow handling from Controller to Cli
  3f6fe1f... Clean up Application.Controller and MainWindow shutdown
  f4f9ff4... Improve logging initialisation and startup
  0eaa3ac... Rework how Application.Client manages application holds
  8f8709f... Add support for opening additional main windows
  1ea97dc... Move global GTK CSS loading from main window to the app
  446e9b8... Always update Application.MainWindow title
  ccb1135... Show HeaderBar close buttons by default