New sensor types

[tdfischer]

Some proposed sensor types:

• 'string' - A boring string of characters
• 'binary' - An ugly blob of base64-encoded binary information, such as a public GPG key, or small picture
• 'number' - Any kind of random number that might be useful (current devices on the network, number of people in the space, etc)
• 'json' - A string of raw JSON. Not a JSON structure embedded in the sensor structure, but properly quote escaped JSON in an otherwise normal 'string' sensor.
• 'boolean' - A true/false sensor (is the garage door open?)

Additionally, a proposal that non-standard sensor types must begin with 'x-', such as 'x-some-json-struct'.

We'd like to use this as part of our Spiff project: https://github.com/synhak/spiff

Among other things, Spiff provides space users with a really stupid simple REST API for posting arbitrary sensor data to the site, which is then logged and made available to anyone else who wants to do cool stuff with available sensors.

[rrix]

Sounds sane enough; can you update the documentation and submit a pull request?