Revert "First step in workflowisation of groups"

This reverts commit 816c998c26ed7cdf6db0b78a922d97c7e2360fc9.
fetcht he correct id of change request
minor graph ehancement
Backend to forbid change request commit when current state diverged
Merge remote-tracking branch 'ncharles_origin/proto/workflows' into proto/workflows
Merge remote-tracking branch 'vme_origin/proto/workflows' into proto/workflows

Conflicts:
	rudder-core/src/main/scala/com/normation/rudder/services/workflows/WorkflowService.scala
Merge branch 'proto/workflows' of git://github.com/fanf/rudder into proto/workflows