BP #22 Provide Bulk download

I've modified BP #22 [1] based on Phil's guidance [2] and referring to the
earlier templates.  Hopefully this helps.  I've noticed a bit of language
confusion between Bulk Access and Bulk Download in the Best Practice
document.  Perhaps I was a contributor there, regardless it needs to be
more consistent.

Thanks,

Eric S.


References

[1] http://w3c.github.io/dwbp/bp.html#BulkAccess
[2] http://lists.w3.org/Archives/Public/public-dwbp-wg/2015Jan/0303.html