[meta] Improve web development experience

Potential developers of web applications use a different set of tools from the ones we traditionally provide in AGL for native apps. There are many things that could be done to bridge the gap between AGL and web developers.

We currently provide the remote web inspector but it's still hard to modify and redeploy an app. Some ideas in that front:

• Add support for some kind of deploy/update/reload cycle
• Provide standard web-dev tools to package and sign agl widgets
• Provide templates for webapp recipes for the most common web-dev environments