Create Development Mode in HUD

[dscrobonia]

Creating an option that will change settings in the HUD to allow easier deving in the HUD. Things to look at are:

• turning off caching in the service worker
• removing cache headers from ZAP
• #80 will help
• looking into service worker life cycle for more consistent updating/restarting of service worker.

[psiinon]

The ZAP side of this should be implemented by #94

[psiinon]

We do now have a dev mode for the HUD, but it might not yet support all of these features...