[FIX] #838 Follow mode states are not cleared when users leave the
session 

Added missing logic to handle user left events.

Change-Id: Ie5d18be29aa42fe2a243c60ae2b14ef1ce036642
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1979
Tested-by: Jenkins CI
Reviewed-by: Franz Zieris <zieris@inf.fu-berlin.de>
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>
[UI] Adds Wizard pages.

Adds concrete classes for wizard pages.

Change-Id: I179ae8e70d8f64778661614623ab72d5ba29d0c8
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1971
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>
Reviewed-by: Holger Schmeisky <google@schmeisky.com>
[FIX] #839 Editor Annotation still remains even when the file is closed 

Change-Id: I7e394a27774d018d44b4dd9bdd62a84500ce218e
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1980
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>
[UI] Adds Wizards.

Adds AddProjectToSessionWizard and JoinSessionWizard.

Change-Id: I47c07c1ca948691b8f2ed4720ef85b09bca01e57
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1972
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>
Tested-by: Jenkins CI
Reviewed-by: Holger Schmeisky <google@schmeisky.com>