Crypto Error Fixed

If you are using node .9 or greater, there was an error with the crypto libs. I've adjusted the code and made the fix. 

oscar.js:2676
          hash[i] = oldhash.charCodeAt(i);
                            ^
TypeError: Object �&Ϲ�����&��҂ has no method 'charCodeAt'
    at OscarConnection._login (/node_modules/oscar/oscar.js:2676:29)
    at /node_modules/oscar/oscar.js:2653:62
    at process._tickCallback (node.js:415:13)