hover links fail to appear due to incorrect json parsing (patch included)

Was having difficulty getting admin:hover to show hover links on certain pages. Not sure what's special about my page, but I tracked it down to response.status being set to 0 after Drupal.parseJSON was called, despite the raw response clearing showing that status was true.

It looks like Drupal.parseJSON is deprecated anyway, so the attached patches (for both 1.0 and dev) simply use jQuery's internal json parser instead, which seems to fix the issue. The patches are both for admin_hover.js