Added modulepath to puppet, and some code for IaaS persistent storage.
Messaging refactoring from V. Zurczak.
Merge remote-tracking branch 'gibello/master'

Conflicts:
	roboconf-iaas-openstack/src/main/java/net/roboconf/iaas/openstack/IaasOpenstack.java
Merge pull request #72 from vincent-zurczak/master

Complete merge from Pierre-Yves