Adds resonsive video support to BuddyPress

Buddypress uses it's own filter on oembeds, https://buddypress.trac.wordpress.org/browser/trunk/src/bp-core/bp-core-classes.php#L2059, this adds jetpacks responsive video support to BuddyPress
Merge pull request #1225 from lakrisgubben/master

Adds responsive video support to BuddyPress