Add more specific item type filters

Add more specific item type filters, "EBOOKS" (just electronic
books) and "PBOOKS" (just physical books).

Signed-off-by: Jeff Godin <jgodin@tadl.org>
Add large print and audiobook item types

Add new item types, "Large Print" and "Audiobook"

Signed-off-by: Jeff Godin <jgodin@tadl.org>