Migrate all the messaging logics into the messaging module
+ Replace the technical interface by business interfaces
+ Add a message type for model restoration
+ Add unit tests related to the messaging logic
Update a constant location
Merge remote-tracking branch 'origin/master'
Remove useless exceptions in the IaaS API
Update the plug-in API
Rename the "local" IaaS into "in-memory"
Update the agent with the new messaging
Add the exception class to the index (!!)
Add the message processor to the index (!!)
Complete the integration with the DM
Fix unit tests and some FindBugs warnings
Complete unit tests in the DM and the REST client
Merge remote-tracking branch 'origin/master'

Conflicts:
	roboconf-agent/src/main/java/net/roboconf/agent/internal/MessagingService.java
Make sure the DM is connected before performing some actions
Merge remote-tracking branch 'origin/master'

Conflicts:
	roboconf-agent/src/main/java/net/roboconf/agent/internal/AgentUtils.java
Add missing classes (thanks EGit, I finally found the option!)
#64 Sort instances
Fix regressions in the life cycle management
Try to fix an OS specific issue
Try to fix another unit test that fails on Oracle JDK 7