tor/changes/bug7359

  o Minor features (controller):
    - Extend ORCONN controller event by ID parameter and add four new
      controller event types CONN_BW, CIRC_BW, CELL_STATS, and TB_EMPTY
      that shall help understand connection and circuit usage.  The new
      events are emitted in private Tor networks only.  Implements
      proposal 218.  Resolves ticket #7359.