Some non-breaking changes to help create rails engine

I am currently trying to create a rails engine to use the ghost client without the server (soon to be open sourced) and there are just two minor incompatibilities I would like to fix.

1. Trailing slashes on the backbone router breaks links
2. Extract the bourbon import into a seperate file, to allow using the bourbon gem.

These are just minor, but if they cannot be fixed then it is cool, I will just need to maintain a separate fork.

Cheers
Graham