Add mozrunner and dependencies from mozbase

- Remove mozrunner directory.

- Add mozbase directory which contains mozrunner from mozbase and all of
  its dependencies.

- Update PYTHONPATH in bin/cfx and activate scripts to be aware of the
  mozbase directory.

- In cuddlefish/runner.py invoke mozprofile with focusmanager.testmode
  disabled and use_staged_dir=False

- Add MOZ_CRASHREPORTER_NO_REPORT=1 env variable in cuddlefish, remove
  MOZ_NO_REMOTE (it's already set by mozrunner)

- Fix build_xpi logic in cuddlefish/xpi.py. It would add blank dirs to
  the xpi before, confusing the new mozprofile.
mozprofile (commit to upstream mozbase): add use_staged_dir option to Profile constructor
mozprocess (commit to upstream mozbase): various fixes in processhandler.py