numeric accuracy and to reduce compuatitonal load. With this commit,
the numeric rounding is fixed not only for the M221 G-code
(as implemented by the preceding commit), but also for the volumetric
extrusion in general.
Removed the old FILAMENT_SENSOR code, which served the purpose
to modulate the volumetric multiplayer in real time depending
on the measured filament diameter. This feature will certainly not be
used by Prusa Research in the near future as we know of no sensor,
which would offer sufficient accuracy for a reasonable price.
