Added Bower configuration and Gruntfile

Hello, 

as promised here are the changes to have your "observableDictionary" as a Bower dependency. This commit includes a Bower package description (bower.json) and a Grunt configuration (package.json & Gruntfile.js).

All you need to do now is installing "node.js" (http://nodejs.org/). If you have "node" then you can install Grunt via the command-line with: ```npm install -g grunt-cli``` and Bower with ```npm install -g bower```.

If you have grunt installed then you should go to your project via command-line and execute:
```
npm install
bower install
```

These two commands will resolve external dependencies (like Knockout). You can then open the ```index.html``` file to see if the needed dependencies have been resolved. :)

If you want to create a package for distribution of your plugin, then just run:
```
grunt default
```

Grunt will package your plugin to the "dist" folder including the source files, a minified version and a source-code mapping file. :) If you are happy with that, then just create a new Version of your plugin on GitHub and release it as a Bower package, using:
```
bower init
bower register knockout.observableDictionary git://github.com/jamesfoster/knockout.observableDictionary.git
```

Feel free to contact me if there are any problems!

More information:

- [Getting started with Grunt](http://gruntjs.com/getting-started)
- [Meet Bower: A Package Manager For The Web](http://devhike.blogspot.de/2013/06/how-to-register-your-library-or.html)
- [How to register your library or component in Bower](http://devhike.blogspot.de/2013/06/how-to-register-your-library-or.html)
I think we could skip the `js` subdirectory since it's only JS lib..