OpenCV is not compatible with python-virtualenv

[RobertKolner]

This leads to a funny problem with multiple possible solutions:

• Install everything globally. Yuck.
• Decouple cam.py from everything else, use HTTP for communication between modules, run web server separately from the camera worker. A lot less yuck, but complicated.
• Dockerize. Probably the best compromise. Also allows us to use OpenCV and DLib at the same time with no installation quirks.

[nikolaik]

+1 dockerize

[nikolaik]

Decoupling makes a good step two, moving cam.py to a module running in it's own process with asyncio, tornado or twisted.

[nikolaik]

See #6

[RobertKolner]

Solved by #7.