apply rule warmStart also when fire is burning

enabled rule "tooRich" again since in can be useful, but with higher ...

thresholds

disabled rule "tooRich" because it does not seem to be a good idea to ...

give more air when the combustion is rich

removed dir warm_start and added rule warmStart instead, tweaked and ...

simplified rules again, adjusted and added tests

further improved rules, adjusted tests, added test

some more tweaking of rules and adjusted some tests

fixed/tweaked again the rules

adjusted rules: wait longer for oxygen sensor to be heated up and give ...

it more time to heat up, time out the sensor heater after 15 mins if
there does not seem to be a fire, switch the heater on if it is off and
not faulted and it seems obvious there is a fire burning, decreased the
min. temp the oven is expected to reach to 700°C, consider the fire
burning if it either reached that min. temperature or if lambda is below
2.

commented constants in rules

added fire dir "burning" and "warm_start", initial impl. of rules for ...

warm start, use constants in rules, added assertNull and assertNotNull

initialize prev measurements with current measurements, updated TODO

allow switching to 8 MHz, use bit shift instead of division to calculate ...

time, poll button every 32 ms instead of 16 ms, some other small
improvements, adjusted tests

don't include avr/power.h for now

use enums instead of constants, rename "heating" to "heater"

moved button, beeper and heater pin settings to pins.h, maintain airgate ...

position in rules, added "tooLean" rule, show fire "direction" together
with current measurements

adding tests + some minor cleanup and improvements

missing German translation

added/improved/fixed some tests, some related small fixes and ...

improvements

don't measure, update and display lambda when heating is not ready since ...

these measurements are useless

completely avoid using lcd_clear() since it sometimes garbles the ...

display, set HEATING_READY_MA to 1400 - at 1500 it is not fully warmed
up

added menu item/display position showing oxygen sensor heater current

replace a (rather expensive?) division in each iteration of the main ...

loop with a (less expensive?) addition

increment timebase and update display according to simulation data

updated TODO

moved formatting of time to module interrupts

removed TODO/comment

added menu position showing the time since last start/reset

compensate ADC non-linearity, update measurements also when heating is ...

off, added some comments

try to make sure the display is cleared before last text is displayed, ...

minor improvement, added TODO

fixes and improvements for oxygen sensor heating control