[Azoth] Added UnreadQueueManager::messagesCleared() signal.

For #1445.
[Azoth] Delegated managing unread count to UnreadQueueManager.

For #1445.
[Azoth] IProxyObject::MarkMessagesAsRead() for #1445.
[Azoth Xoox] Removed messagesAreRead() signal.

It's not used anywhere anyway.
[Azoth Xoox] Truly mark messages as read on forwarding.

This probably closes #1445.
Merge pull request #300 from Maledictus/master

[SB2] fix property type conversation
[LastFMScrobble] Updated plugin description.
[SL] Added Scroblibre plugin stubs.
Merge branch 'master' of github.com:0xd34df00d/leechcraft
[SL] Added AccountsManager.
[SL] Have settings.
[SL] Added Util header.
[SL] Fixed saving settings.
[SL] Emit services on addition, split load after init.
[SL] Added SingleAccAuth handler.
[SL] Added AuthManager.
[SL] Instantiate accounts manager and auth manager.
[SL] Fixed reauth control flow.
[SL] Added SubmitInfo struct.
[SL] Removed the Password column.