New State Machine which is ready for autoscale.

Squashed commit of the branch feature/autoscale-US1 (https://github.com/slipstream/SlipStreamServer/tree/feature/autoscale-US1)
from https://github.com/slipstream/SlipStreamServer/commit/4d6b54cfcd1fbfd41a641d06a6840de3420f53c9
to https://github.com/slipstream/SlipStreamServer/commit/dbb1af6ff38de077e60e4d50903ce6411cb37a12

This commit also feature the following:
 - Rollback the transaction if an exception is raised during the merge or during the commit.
 - Updated the launch timeout from 1 minute to 5 minutes because some connector takes time to do the launch (especially connectors who use SSH to do the contextualization).
 - Removed the runtime parameter named "statemessage".
 - Updated the garbage collector interval to 5 minutes.
 - New logic for the garbage collector.
 - When a Run based on a Deployment is created the RuntimeParameters coming from the Cloud specific configuration are filtered with the cloudservice of each node.
 - Fixed some bugs in the OpenStack connector.