I also relaxed the parsing rules a bit, so now it will work with @user/permlink as well:
https://phist.steemdata.com/history?identifier=@sneak/re-neoxian-running-steemit-locally-update-20170217t033415071z
You can also use full URL's (incl. reply-to urls)
https://phist.steemdata.com/history?identifier=https%3A%2F%2Fsteemit.com%2Fsteemdata%2F%40furion%2Fthis-app-shows-you-edit-history-for-any-post%23%40sneak%2Fre-furion-this-app-shows-you-edit-history-for-any-post-20170217t041019279z
We're gonna drop both the category and the @-symbol from the URLs on steemit.com pretty soon, so it'll just be
/username
and/username/permalink
. Maybe a month or two.