Point feeds to TPAC instead of slimpac or JSPAC

Where possible, point to TPAC endpoints for HMTL output of supercat feeds.

Also, just use the bookbag (container) name for bookbag feeds, instead of
wrapping them in formatting and context.  The description element already
provides that.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>