Extend Bootstrap grid and components to project.

[jaclynperrone]

This commit features css refactoring in favor of @extending Bootstrap grid and components. Some things will look different (ie. buttons, selects, VCF table), but for the most part the original styling is intact. This makes it easier to merge it into master, for there aren't any major interface changes.

There are some markup changes in the .js files, but nothing more than adding/removing/renaming classes & elements.

The final thing to do is update all the screenshots, which I have not done yet.

[ihodes]

Awesome! Can you run the pdiff tests on this? (I'd love to see what this looks like :))

[ihodes]

Looking good—a few comments, & I'd love to see this this in action/see the pdiff screenshots.

[ihodes]

LGTM, merge away!