Use YAQL to generate MuranoPL object model from plain data.

This commit contains all the needed changes to generate AD object
model shown on
https://github.com/istalker2/MuranoDsl/blob/master/ad.json from the UI
definition shown on http://paste.openstack.org/show/74322/

Changes in dynamic UI format:
* added 'Version' field to distinguish the actual format - all the
  definitions without it are considered to have Version=1
* added 'Templates' field (more flexible analogue of 'unitTemplates'
  field which was dropped) - for keeping reusable pieces of Object
  model
* added 'Application' field which defines the final Object model
  (possibly using template snippets from the 'Templates' secion)

Also drop 'instance' field type because all its postclean logic is now
superseded with YAQL processing of 'Application' section.

Change-Id: I92e4d771da2e68e1b9cb41e01dfd8e9ef05cb796
Implements: blueprint dynamic-ui-augment
Merge "Use YAQL to generate MuranoPL object model from plain data."