Convert BoundedInt value from json into int

Wsme doesn't convert automaticaly the value of a UserType into
its basetype. This changeset do it

Change-Id: I7402e144e6a337bbed13789c1611a163bbf9ba61
Notify with string representation of alarm reason

Fixes bug 1227668

Ensure string representation of alarm reason is passed to the
alarm notifier over RPC (as opposed to a gettextutils.Message
instance).

Change-Id: I6a840789f83068ee5721cb139b06cf0071240152
Add alarm combination API

This change add a new type of alarm in the API for creating
alarm that combine the state of other alarms.

Implements blueprint alarming-logical-combination

Change-Id: I3203ae6143f5e21b5160a9a04692e7a4c8e550b8
Implement the combination evaluator

The implementation of the combination evaluator.
'and' and 'or' operations are allowed.

Implements blueprint alarming-logical-combination

Change-Id: Ie6b7dedc8aa5debb250c83e1c6db05c0d66eea1b
Provide new API endpoint for alarm state

This patch add a new endpoint to the alarm API to change only the state
of an alarm. And modifies the evaluator base to use this new endpoint.

Implements blueprint alarming-logical-combination

Change-Id: I8bff74f0686ba17103ee63bcbdb0830c8273596f