Support installs via NPM

[dansomething]

No description provided.

[troywarr]

+1 please.

This would make the repo name a misnomer, so I might suggest either:

1. renaming the repo to something like bootstrap-packaged
2. creating another repo named bootstrap-npm to house a version containing package.json in lieu of bower.json

#1 seems preferable as it keep things centralized/DRY.

FWIW, this seems like an increasingly common use case with the rise of the npm/Browserify packaging approach (vs. Bower/RequireJS).

[Foxandxss]

Let's continue in #60