Update from master with following commits

* Fix log.exception usage. Add log translating
  Closes-bug: #1264980

* Add per-tenant isolation
  Implements blueprint per-tenant-isolation

* Fixed issue with Key Pairs for Linux-based services
  Implements: blueprint rewrite-key-pair-for-linux-based-services
* Add service_definition directory existence checkup
  Closes-Bug: #1269431

* Make some refactoring

* Add forgotten return
  Closes-Bug: #1249303

* Add forgotten return statements
  Closes-Bug: #1268934

* Fix error code when there is no input json

* Return correct http code
  Closes-Bug: #1268976

Change-Id: I726d8b8849b2ccd44fdbf9d7b4ce65f3a62cf4aa