More changes and additions to the reviews section

I have encoded and posted a short review of Whitman's "Shirval; a Tale of Jerusalem" that was brought to our attention by Adam Bradford (http://whitmanarchive.org/criticism/reviews/shirval/anc.00612.html). Since this is the first review of one of Whitman's shorter fictional works, I have added a new category on the index page for the reviews titled "Reviews of Individual Stories."

I have also revised a review of Leaves of Grass (1855) titled "A Strange Blade," which we originally thought first appeared in the National Anti-Slavery Standard, but which was in fact first published in Punch Magazine, as Eric Conrad has discovered (http://whitmanarchive.org/criticism/reviews/leaves1855/anc.00338.html). The information about the review's subsequent publication is documented in an editorial note.

-Vanessa