Added grunt to combine and minify CollidR.js

Using Gruntfile as per
http://blog.simontimms.com/2013/12/30/grunt-your-asp-net-builds/
Using Post Build event to copy CollidR.js and CollidR.min.js files to
the sample MVC application.
Added CollidR.js and CollidR.min.js to .gitignore
Moved xcopy command inside of batch file

needed to do this to ensure that build errors in the grunt task would
cause the build in VS to fail
Merge pull request #50 from MisterJames/javascript-bundling

Closes #49. I'm not sure if there's a better way to do it, but when you pull the branch down the sample project is missing the referenced JS files (because you're rightly ignoring them in gitignore). I'm okay with this for now, unless you have any other ideas. Thanks for this @dpaquette!