Update to conform with FB code style

Summary: This updates rebound to (almost) conform with our FB internal linter. The other issues ('setImmediate' is not defined etc.) don't make sense to be fixed in the open source version.

Test Plan: Opened examples/index.html locally and ensured all the demos still work
No but it seemed like the only way to make this fit within the 80 character limit. Do you have any suggestions?