Design Doc for Sample dApp

[windley]

The sample dApp should demonstrate several important features:

• makes use of both picos and their associated pod
• is just javascript that can be run from anywhere (even local file)
• has no local, long-term storage (i.e., ok to use browser localstorage for session info

The backend should be architected to make use of and highlight features of picos and pods.

This diagram shows the "stack" for this application. This issue concerns the top two which use the bottom two.