Roll-back of #595084; type-hinting parameters at stdClass makes it so you can't ever pass in another type of class.

#326539 by JohnAlbin, sun, cha0s, ultimateboy, Rob Loach, Damien Tournoud: Convert 'class' attribute to use an array, not a string.

#376129 by boombatower, Damien Tournoud, and chx: Change getInfo() to a static method to reduce memory footprint of SimpleTest.

  Drupal core!  This is an important milestone for the project so enable
  the module and check it out ... :)

  Thanks to Rok Žlender, Károly Négyesi, Jimmy Berry, Kevin Bridges, Charlie
  Gordon, Douglas Hubler, Miglius Alaburda, Andy Kirkham, Dimitri13, Kieran
  Lal, Moshe Weitzman, and the many other people that helped with testing
  over the past years and that drove this home.

  It all works but it is still rough around the edges (i.e. documentation
  is still being written, the coding style is not 100% yet, a number of
  tests still fail) but we spent the entire weekend working on it in Paris
  and made a ton of progress.  The best way to help and to get up to speed,
  is to start writing and contributing some tests ... as well as fixing
  some of the failures.

  For those willing to help with improving the test framework, here are
  some next steps and issues to resolve:

    - How to best approach unit tests and mock functions?
    - How to test drupal_mail() and drupal_http_request()?
    - How to improve the admin UI so we have a nice progress bar?
    - How best to do code coverage?
    - See http://g.d.o/node/10099 for more ...