* Add an Attachments collection filter for uploadedTo (post_parent).
* Correct an erroneous map from the non-existent parent prop to post_parent.
* Define default menuOrder and uploadedTo props for uploading attachments.
* Unify filterable props into a single method (improving validation performance for calls to set with multiple properties).
Props koopersmith
fixes#22654
git-svn-id: https://develop.svn.wordpress.org/trunk@22951 602fd350-edb4-49c9-b593-d223f7449a82