arduino/Plotter - doubled the movement speed (should still be slow enough)
arduino/SubstepMotor - added support for coordinates down to -1000 ("fixed" rounding problems for negative numbers)
cpp - main - added commands preprocessing, bounding box detection and errors when the drawing is broken in any way
	- command - a simple structure holding a single HPGL command
removed Makefile from the repo (autogenerated by CMake)