This pull request removed Zend_Registry from core by replacing it with an own simplistic Registry implementation in core/Registry.php.
I didn't yet comment the code in core/Registry, but will do so once merged.
Suggestions/Feedback?
Hm. That test failure is interesting. It shouldn't happen.
Nice change... Build failed maybe because you removed the file 2.0-a7.php ?
Guess there is an 'use Piwik\Registry' missing in FrontController.php
Good catch, but sadly not the reason for test failure. For some reason the with entry in the registry vanishes.