[geary: 27/27] Merge branch 'mjog/user-plugins' into 'mainline'

[Michael Gratton <mjog src gnome org>]

commit 3f81b7d5077b5c75877154ef6d5bd7bf84d46e0c
Merge: 902f161c 4b53370a
Author: Michael Gratton <mike vee net>
Date:   Tue Mar 17 08:45:46 2020 +0000

    Merge branch 'mjog/user-plugins' into 'mainline'
    
    Support optional (non-builtin) plugins
    
    See merge request GNOME/geary!441

 desktop/org.gnome.Geary.appdata.xml.in.in          |   8 +
 desktop/org.gnome.Geary.gschema.xml                |   6 +
 meson.build                                        |   1 +
 po/POTFILES.in                                     |  15 +-
 src/client/application/application-client.vala     |  20 +-
 .../application/application-configuration.vala     |  15 +
 .../application/application-contact-store.vala     |  14 +-
 src/client/application/application-controller.vala | 148 +----
 .../application-folder-store-factory.vala          | 282 ++++++++++
 .../application/application-main-window.vala       |  13 +-
 .../application-notification-context.vala          | 596 ++++++++++++++-------
 .../application/application-plugin-manager.vala    | 310 +++++++++--
 .../components/components-preferences-window.vala  | 148 ++++-
 src/client/folder-list/folder-list-tree.vala       |  99 ++--
 src/client/meson.build                             |  15 +-
 .../desktop-notifications.plugin.in                |   3 +-
 .../desktop-notifications.vala                     | 260 +++++----
 .../folder-highlight/folder-highlight.plugin.in    |   4 +
 .../plugin/folder-highlight/folder-highlight.vala  |  95 ++++
 src/client/plugin/folder-highlight/meson.build     |  26 +
 src/client/plugin/meson.build                      |   1 +
 src/client/plugin/messaging-menu/meson.build       |   2 +-
 .../plugin/messaging-menu/messaging-menu.plugin.in |   3 +-
 .../plugin/messaging-menu/messaging-menu.vala      | 109 ++--
 .../notification-badge.plugin.in                   |   5 +-
 .../notification-badge/notification-badge.vala     |  86 +--
 src/client/plugin/plugin-account.vala              |  21 +
 src/client/plugin/plugin-application.vala          |  20 +
 src/client/plugin/plugin-contact-store.vala        |  41 ++
 src/client/plugin/plugin-email-store.vala          |  27 +
 src/client/plugin/plugin-email.vala                |  53 ++
 src/client/plugin/plugin-error.vala                |  27 +
 src/client/plugin/plugin-folder-store.vala         |  32 ++
 src/client/plugin/plugin-folder.vala               |  40 ++
 .../plugin/plugin-notification-extension.vala      | 148 +++++
 src/client/plugin/plugin-notification.vala         |  29 -
 src/client/plugin/plugin-plugin-base.vala          |  47 ++
 src/client/plugin/plugin-trusted-extension.vala    |  40 ++
 src/client/util/util-email.vala                    |   2 +-
 src/engine/api/geary-base-object.vala              |   2 +-
 40 files changed, 2126 insertions(+), 687 deletions(-)
---