TaskHub: Add convenience function to add a task and clean up users

Change-Id: I5c76f8af720092d4e47b1a9fa889fb3a7010f21f
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Debugger: Fix configuration upgrade path from 2.8

Change-Id: I67547dfad529ebb918741721b691c39bb0e69720
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
PluginManager: Small docs update

Change-Id: I0d0e021a272f818746d2482a5ba0c536bf125539
Reviewed-by: hjk <hjk121@nokiamail.com>