Merge changes from topic 'cherry-pick form master to RFC8040' into stable/boron

Merge changes from topic 'cherry-pick form master to RFC8040' into stable/boron

* changes:
  Clean up Rfc8040
  Bug 7735 - Update restconf models by RFC 8040
  Bug 7429 - Upgrade docgen in restconf to the latest draft of ietf-restconf
  Bug 7206 - Chinese improper code problem.
  Bug 5679 - implement new service RestconfService
  Bug 5679 - add new module ietf-restconf
  Bug 5679 - implement ietf-restconf-monitoring - cleanup
  Bug 5679 - implement ietf-restconf-monitoring - streams
  Bug 5679 - implement ietf-restconf-monitoring - capabilities
  Bug 5679 - prepare constants for ietf-yang-library model
  Bug 5679 - add new module ietf-restconf-monitoring to restconf
  Bug 5679 - fix generating of schema by ietf-yang-library and path of RestconfSchemaService
  Bug 5679 - ietf-yang-library module implemetation
  Bug 5679 - prepare constants for ietf-yang-library model
  Bug 5679 - new module 'models' for new models in restconf
  Bug 5679 - renamed package rest.services to base.services
  Add missing yang - sal-remote
  Do not attempt to construct invalid QNames
  Bug 7231 - Upgrade ietf-restconf draft17 to draft18
  Bug 7207 - Bad parsing of identityref in typedef for last ietf-restconf draft
  Bug 6951 - Implement Query parameters - with-defaults
  Bug 6947 / Bug 6948 - implement point and insert query params
  Bug 4883 - implement query parameter - filter
  Bug 6949 / Bug 6950 - Implementation of start-time and stop-time query parameters
  Bug 6935 - RPC in latest draft doesn't work - problem of parsing to instance identifier
  Bug 6995 - Change event notification subscription usability PART2
  Bug 6995 - Change event notification subscription usability PART1
  Bug 6903 - Implement Query parameters - fields
  Bug 6895 - Implement Query parameters - depth
  Bug 6382 - add apidoc for latest restconf draft
  Bug 6731 - add valid example values
  Bug 6931 - Fix unsupported specific type of leaf
  Use UTF-8 as the standard output
  InstanceIdentifierCodecImpl JUnit test
  Bug 6679 - api explorer creates false examples
  Bug 6272 - support RESTCONF PATCH for mounted NETCONF nodes
  Bug 6746 - Restconf: Not working GET operation on mount points
  Fix close() in provider