o First implementation acceleration. severl TODOs left:
  - Double number of steps again
  - Substact calculation overhead
  - acceleration planning in machine control.
  - make gcode-stats calculator take acceleration into account.
o Update README to reflect addition of acceleration.
o Allow for 'infinite acceleration', i.e. always use travel speed.
o A bit better documentation of the assembly.
o Do (estimated) correction for calculation overhead.
o Fix some whitespace alignment.
o comment update: expand don't and we're to do not and we are.
o Properly calculate the euklid distance without integer overflow issues.
o Explicitly use the motor bit defines to set output direction.
o Proper use of volatile.
o make beagleg_wait_queue_empty() aware that there are more than 2 states
  now. So we can't wait while FILLED, but must wait while !EMPTY.
o somehow the slashes in URLs were converted to ;;
o When outputting informal messages, prepend //
o Some dummy implementation of 'get temperature' M105
o Impl: get position M114; Get firmware version M115
o G-Code parser: also prepend (error-)messages with //
o Temporary: adapt count properly.