Pass in most dependencies to Server.

Remove all static/singleton references in the constructor so that
Servers can be instansiated sensibly without all the client existing.

Also change everything that creates a Server to use the appropriate
method in the ServerManager instead of doing it manually.

Depends-On: I3fff818d6e6694163660a36f47d60271d8f0e68e
Change-Id: I9842c20b4e4ff846c9bbf4858da794a843c3b053
Reviewed-on: http://gerrit.dmdirc.com/2655
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager
Update submodules: plugins (new commits)

plugins:
    74402de Chris Smith <chris@dmdirc.com>
            Update plugins after core Server changes.

            Depends-On: I9842c20b4e4ff846c9bbf4858da794a843c3b053
            Gerrit: http://gerrit.dmdirc.com/2658

Change-Id: I4428f7b1540887f27bc7d27d300af242c72690b8