implemented get_zones_for_post

[smichaels]

hi...a client had a need for this functionality, so I went ahead and implemented this function per your TODO.

thanks!

Sean

[GaryJones]

Thanks!

The conflicts would need resolving after all this time.

Would love to see some tests for this.

Copying the TODO notes here:

// get_object_terms
// get_terms

// OR

// get all meta_keys that match the prefix
// strip the prefix

// OR

// get all zones and see if there's a matching meta entry
// strip the prefix from keys

// array_map( 'absint', $zone_ids )
// $zones = array();
// foreach( $zone_ids as $zone_id ) {
// $zones[] = get_zone( $zone_id );
// }
// return $zones;