Now when a connector needs to be used it is copied.
The Dashboard will not crash if a connector is misconfigured.
Minor fix on OpenStack to solve a possible problem.
Merge branch 'master' of https://github.com/slipstream/SlipStreamServer
Removed "cloud.connector" prefix in system parameters.
Reshuffled (User,System,Image) parameters in all connectors.
Merge branch 'master' of https://github.com/slipstream/SlipStreamServer

Conflicts:
	jar/src/main/java/com/sixsq/slipstream/connector/openstack/OpenStackConnector.java
Now system parameters are merged by default into User object except on the web interface.
Minors in StratusLab parameters.