Merge changes from topic 'api-tests'

* changes:
  BranchApi: Implement get and delete
  AbstractDaemonTest: Simplify helpers for getting changes
  Delete StarredChangesIT
  IdentifiedUser: Clear starred changes before rereading from API
  Implement list branches extension API
  Convert HashtagsIT to extension API
  Convert most of CreateProjectIT to extension API
  Convert GetAccountIT to extension API
  Convert CreateChangeIT to extension API
  Convert CommentsIT to extension API