* switch --resultlog to --junit-xml in testrunner/runner.py, lib_python_tests.py,
  pypyjit_tests.py, and buildbot/bot2/pypybuildbot/builds.py; rewrite
  should_report_failure() in runner.py to detect crashes by checking for a
  valid XML testsuite rather than resultlog F/E/P lines
* convert the last space.realunicode_w() user, posix.interp_posix:158, to
  unicode_w, then drop realunicode_w from baseobjspace.py and gateway.py
* review all uses of W_Unicode.text_w, right now it is exactly W_Unicode.utf8_w.
  It shoud only return valid utf8 (see 0be26dc39a59 which broke translation on
  win32 and failed tests on linux64). Then we can use it in places like
  _socket.interp_func:322 instead of space.encode_unicode_object(w_port,
  'utf-8', 'strict')
