Merge changes Ic66d8fcd,I9ffbe874,I59e6926b,I1fb172f7,I0eb60ace, ...

* changes:
  Add some wait commands inside PyHal
  Simplify scan parameters & start/stop
  Simplify le random address setting for tests
  Simplify le connection logic for SimpleHalTest
  Simplify Le connect logic for SimpleHalTest
  Simplify advertisement in SimpleHalTest
  Add HciMatchers.Exactly, for more compact tests
  Add HAL reset helper
  Add advertisement abstraction in PyHal
  Add an advertisment abstraction to PyHci