Remove dependency on libudev.h
Remove dependency on libudev.h

libudev is linked explicitly and only a few structures need to be declared which are passed as pointers to the dynamically loaded functions. No need to require libudev-dev on the build machines.
prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r