Fixed adata encoding bug.

Apparently a thing happened where the authentication tag would never verify if a bit array was passed in because it was being authenticated as a normal bit array, but checked as a base64 string.  Now adata is *always* encoded in base64, instead of no encoding for strings and base64 for bit arrays.

Found it while working on the wiki.  The `sjcl.js` has been recompiled and all tests pass.

Also, my editor did a bunch of spacing fixes without telling me.  You're welcome?  I'm terribly sorry?  :confused: