update doc, sync in with current AppState code & workflow
rolehistory.md: This is the design and algorithms to be implemented, with core reload algorithms defined.
The specifics of the callbacks are not completely specified (there's a lot of complexity in the existing code to address all code paths), and
Merge branch 'feature/BUG-9267' into develop
Merge branch 'develop' of github.com:hortonworks/hoya into develop

# By tedyu
# Via tedyu
* 'develop' of github.com:hortonworks/hoya:
  BUG-10406 Give ClientProvider ability to report the location of active master