[Feedback] Update Sha1.js

The sha1.js file in SMF and Elk are from http://pajhome.org.uk/crypt/md5  The version of this file is 2.1 and its from 2002 (actually there was a 2.1a that should have been used).  There was also an update to version 2.2 in 2009 and thats what is in this commit.

We don't really use most of the functions in the file, but wanted others to see if they also felt that this should be updated.  From some quick testing it appears to work just like 2.1 but would like some others to give it a test as well.  The diff looks worse than it is due to spacing, you can get the 2.1 and 2.2 versions at the link above and also read the changelog on that page.

Also since this is a standalone library file that we have not touched, I don't think our header should be on it, only the original authors header (its not inside of one of our files with other functions etc).  If it was contained inside of another file then the header would be fine (thats also an I think, so feedback is welcome, just want to do the proper thing)