Update jQuery.maskedinput to use GruntJS instead of Jake

The grunt build will automatically pick up new spec files and executes via the command line. You'll need to install the `grunt-cli` npm package globally to run the grunt build:

    $ [sudo] npm install -g grunt-cli

Then just install the npm packages specified in the package.json and run the grunt build.

    $ npm install
    $ grunt

Some further questions/thoughts:

 * do we care about generating the distribution copies on the `default` build task? Should we use a separate task (`release`?) to do this?
 * the grunt file reads the package description and version from the package.json, if we merge #105 we should change this to take the values from component.json and only use package.json for build dependencies.