The urlencode method breaks accountswitcher for certain passwords

Reported [here](http://www.reddit.com/r/RESissues/comments/1hza18/bug_incorrect_login_andor_password_please_check/).

Replicate
--------------
 * Create a password that contains ``++``
 * Can not use `accountswitcher` module to login

Cause
---------
[L2101:](https://github.com/honestbleeps/Reddit-EnhancementSuite/blob/master/lib/reddit_enhancement_suite.user.js#L2101)

    urlencode: function(string) {
        // Javascript's escape function is stupid, and ignores the + character. Why? I have no idea.
        // string = string.replace('+', '%2B');
        return escape(this._utf8_encode(string)).replace('+', '%2B');
    }

That'll do it.

Potential Fix
-------------------

Use Javascript's inbuilt ``encodeURIComponent`` method for passwords?