Exception when prompt is set hidden = true

[dmaevac]

When the prompt schema includes hidden: true grunt-init errors with the following:

tty.setRawMode: Use 'process.stdin.setRawMode()' instead.

I think this is because grunt-init still uses a version of prompt prior to 0.2.0. tty is deprecated since node 0.8 (http://nodejs.org/api/tty.html#tty_tty_setrawmode_mode). But upgrading to latest prompt causes other errors.

For example:

    init.process({}, [
        {
            name: 'user',
            message: 'Username'
        }, {
            name: 'pass',
            message: 'Password',
            hidden: true
        }
    ], function (err, props) {
        ......