Revert the conversion of adjacent post queries to WP_Query. Explanation on the ticket.

Reverts [27285], [27286], [27287], [27288], [27291], [27292], [27293], [27296], [27633], [27634], [27635], and [27692].

see #26937.


git-svn-id: https://develop.svn.wordpress.org/trunk@27836 602fd350-edb4-49c9-b593-d223f7449a82
Avoid infinite recursion in get_term_children() when a term is incorrectly a parent of itself.

props kovshenin.
fixes #27123.


git-svn-id: https://develop.svn.wordpress.org/trunk@27837 602fd350-edb4-49c9-b593-d223f7449a82