Several changes for core Jig handling:

  * Jig entries in crwbar.yml must declare what class implements them.
  * Jigs are created at barclamp import time, not as part of a
  migration.
  * Jigs can declare what roles need to be present on a node for them
    to be able to take action on a node, and the role addition
    infrastructure will take care of making sure those roles are
    present.
  * Bootstrap and implicit roles will only be added to a node at
  create time if the jigs that implement them are active.
Merge pull request #639 from VictorLowther/pull-req-master-902d456b04f9723fcdadbee1c7540b8a939fc3f1

https://github.com/crowbar/barclamp-crowbar/pull/639

Merged by devtool for VictorLowther