Tinysensor sketch improvements

[jscrane]

• [x] remove pinMode for A1 (not needed)
• [x] remove setAutoAck (not needed)
• [x] constants for ports
• [x] pinMode(A1, INPUT_PULLUP)
• [x] fix sensortest sketch
• [x] setMaxRetries (to save batteries) --- use sensortest
• [x] use Interrupted instead of sleepy

[jscrane]

See this article for some tips. In particular:

• maybe don't use RF24Network at all?
• channel frequency (so don't get interference from wifi)
• lower data rate

[jscrane]

Don't think there's enough flash space for Interrupted. Use a slimmed-down wdt_sleep() instead (see sensortest.ino)