Use phone as the access router

[yyzhuang]

Currently the phone and researcher's laptop has to be on the same WiFi network. If the WiFi network does any packet filtering, the two devices cannot talk to each other. A solution would be to let the laptop connect to the phone that acts as an access router and send information back and forth.

Note that this is only a solution for local experiment, e.g., at workshops or hackathons. When real researchers connect to devices owned by random people, this solution won't work.

[yyzhuang]

This is duplicate with nodemanager's issue #4.