Always convert auto-drafts to drafts in edit_draft() and _wp_translate_postdata().

This regressed due to refactoring in [26995]. This commit fixes Quick Draft.

see #25272.

Built from https://develop.svn.wordpress.org/trunk@27405


git-svn-id: http://core.svn.wordpress.org/trunk@27252 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Multisite load: Properly call wp_cache_set().

props gradyetc.
see #27003.

Built from https://develop.svn.wordpress.org/trunk@27406


git-svn-id: http://core.svn.wordpress.org/trunk@27253 1a063a9b-81f0-0310-95a4-ce76da25c4cd