Add _blank target to bill of rights links
Add _blank target to bill of rights links

Along with being a bit more convenient for the user, this helps
fix the inconvenience of the user having to re-select their age range
on the radio button to re-open the assent/consent area (although
that's also another issue to resolve).

biocore/american-gut-web,biocore/american-gut-web,biocore/american-gut-web