react 0.12.x and react-router 0.11.x compatibility

Started with shitalm's fork https://github.com/mtscout6/react-router-bootstrap/pull/4

Let me know if it needs changes, works great for me
Why are you requiring in the entire react-bootstrap library here?

By isolating the require calls to the specific elements of concern you allow more room for minification tools to only bring in necessary code.