Widgets:
- Prevent dragging of the widget-in-question when the chooser is open.
- Don't show more than one spinner when saving widgets positions.
- Disable selecting of text in the widget title. Prevents selecting/highlighting most of the screen when dragging on slower devices.
See #25821.

git-svn-id: https://develop.svn.wordpress.org/trunk@26306 602fd350-edb4-49c9-b593-d223f7449a82
In `update_meta_cache()`, ensure that meta is always stored in the same order. Removes an unnecessary `$wpdb->prepare` statement. Adds unit test.

Props mattheu.
Fixes #25511.



git-svn-id: https://develop.svn.wordpress.org/trunk@26307 602fd350-edb4-49c9-b593-d223f7449a82