MB-8295: Set active partition in dev view

Add a function to be able to set the current active partition.
It will set all other partitions to cleanup.

Change-Id: I2cacfb611c8cf5ef31ac1ec3b4afad09d7ca049f
Reviewed-on: http://review.couchbase.org/26518
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Volker Mische <volker.mische@gmail.com>