Application Cache and Service Workers

[brehaut]

The Application Cache manifest file (Safari/iOS) and Service Workers (Chrome/Android, Firefox) allow applications to run in offline or be installed as 'applications' on a users mobile device. While Service Workers are the future and more flexible, we also need to support the old dog Application Cache for iOS until such a time as Apple decided to support Service Workers.

This task will require some interaction with the build system ( #3 ) in order to programmatically generate the application cache manifest (development without automated manifest management is basically untenable)

I suggest doing the application cache implementation as it is strictly a subset of what the service workers are capable of.

• Write a build task to generate an application cache manifest.
• Write a service worker to manage caching relevant assets.
• Handle graceful reloads when the application updates via either mechanism

Depends on #3