Comment updates.
Simplify assignment of 'utchour'.
Initialize bit.tlow to -1 to make it obvious that something is wrong if this value is returned in the end.
Add a field bit.tlast0 (initially -1) which records the last timestamp on which the averaged signal (y) is 0.

This can be used to approximate the delay of the algorithm (~50 ms) or to measure signal quality.
Update display for bit.tlast0, drop active-percentage.
Shift fields right of bit.tlast0 two positions to the left.
Remove obsolete variable 'oldtime'.
Unwrap short line.
Record the raw radio signal in bit.signal[]
Major overhaul of readpin, let it use get_bit_live() with the newly recorded raw radio buffer instead of rolling our own code.