add bootstrap

I added bootstrap gem, @import bootstrap etc., and //requires in JS folder.
I believe rather than deleting the application.css file, we want to move it into "application.css.scss".  The twitter bootstrap documentation is pretty horrible with that.

I opened a GitHub bug for the twitter bootstrap sass guys.  You can see it here:

https://github.com/twbs/bootstrap-sass/issues/691

Other than that, this pull request looks solid.