3.7 regression from [25119]: Have in_category() return false when the first argument is empty.

Adds unit tests.

props ericlewis.
fixes #25706 for trunk.


git-svn-id: https://develop.svn.wordpress.org/trunk@25923 602fd350-edb4-49c9-b593-d223f7449a82
In update_option(), call the update_option hook before the DB update.

Reverses a regression from [25664].

props calin.
fixes #25705 for trunk.


git-svn-id: https://develop.svn.wordpress.org/trunk@25925 602fd350-edb4-49c9-b593-d223f7449a82