Allow LIKE comparison for $q['meta_compare']

[johncoswell]

I am working on a plugin that will be doing plaintext searches of a metadata property. It would be helpful to have the LIKE operator available to 'meta_compare' within WP_Query::get_posts so that I don't have to create a new filter to accomplish the same result:

in_array($q['meta_compare'], array('=', '!=', '>', '>=', '<', '<=', 'LIKE'))

[johnbillion]

NOT LIKE and IN would be handy too

[dd32]

See Also: #9124 - meta_compare needs to allow "in" as well

[westi]

Closing as a dupe of #11482 as that is for the same enhancement and has a patch.