Option to export projects to Android and/or iOS

It would be really cool if students could generate links to install their projects as Android or iOS apps on a phone or tablet. The app would be a web view, wrapped as an application with a set of generated files.

Concerns:
- The set of available events would be much smaller. It may be that we should simplify the event model anyway to include just mouse moves, clicks, and drags.
- iOS might not be possible without the student either jailbreaking or getting a $100 developer license. Android would require enabling third-party apps.

Start by defining how project-generated files would support a web view wrapped for Android or iOS, and review the event model concerns in the issue. Establish the platform, licensing, and installation constraints before implementation. Done means students can generate installable links for the supported platform and the reduced event set is clearly documented.

Written by the indexing model from the issue text.