Make Ophan request for non-modern browsers

Ophan is currently init'd inside our core app.js file. This is for various reasons such as the ability to pump in extra data such as A/B tests and component tracking.

A major side-effect of this means user agents which do no "cut-the-mustard" are exempt from Ophan tracking. This obviously is not acceptable.

Therefore, this PR introduces a new decoupled ophan.js bootstrap which is loaded for non-modern browsers.

/cc @tackley @philwills @ironsidevsquincy @gklopper