use local var for _crypto

this fixes a problem "undefined var _crypto" i have when using this with webpack
update sha.js
Merge branch 'patch-1' of github.com:mosch/crypto-browserify
Merge branch 'master' into release
everything should use strict
use sha.js@2.3.0
document the new hash algorithms added in sha.js@2.3.0
fix merge error
return correct list of supported hashes in gethashes
64 bit blocklength for sha512 and sha384
remove console.log
3.5.0