Val check for start/end times

fix None crash for start/end_time

Default, bench

UTC and lcd overdrive options

Ref to adafruit

MCP ada stuff documented

Adapt chronotron for Adafruit's i2c chip mcp23008

Keep bit 0 as input, since unused

Initialize mcp23008 gpios all as output

fix syntax

Remove "offset shouldn't be 0.0" note, since outdated.

More doc

Some documentation added.

Use correct register functions for MCP23008

cleanup mcp stuff, add init