Ensure we have a charset before calling mb_internal_encoding(), avoiding an unnecessary (if suppressed) warning. props dfavor. fixes #23093.
Return WP_Error from wp_crop_image() if saving has failed. props macbrink. fixes #23325.
Update Backbone.js to 0.9.10. props aaronholbrook, fixes #23262.
Update to Services_JSON 1.0.3. props bpetty. fixes #21568.
Stop recommending the init hook in the _doing_it_wrong() message for too-early scripts and styles. Instead, recommend the three _enqueue_scripts hooks. If they're noticing they are doing it wrong, let's push them to 100% correct, not partly correct.

see #22896.
Do not allow accidental or negligent deregistering of critical scripts in the admin. (Defined for now as jQuery and jQuery UI.) Show minimal remorse if the correct hook is used. see #22896.
Mark the string for translation. see #22896.