Workflow event logs
Merge remote-tracking branch 'FAR/proto/workflows' into proto/workflows

Conflicts:
	rudder-core/src/main/scala/com/normation/rudder/services/workflows/WorkflowService.scala
	rudder-web/src/main/scala/bootstrap/liftweb/AppConfig.scala
Add db migration file
Add rule diff V1
Add link to rule diff
Merge remote-tracking branch 'FAR/proto/workflows' into proto/workflows
Revert "First step in workflowisation of groups"

This reverts commit 816c998c26ed7cdf6db0b78a922d97c7e2360fc9.