Fix warnings -Wdelete-non-virtual-dtor
Fix warnings -Wdelete-non-virtual-dtor

Reported GCC warning: deleting object of abstract class type ‘PathObject’ which has non-virtual destructor will cause undefined behaviour [-Wdelete-non-virtual-dtor]
   delete object;


asmuelle/heekscnc,asmuelle/heekscnc,satovey/heekscnc,asmuelle/heekscnc,asmuelle/heekscnc,satovey/heekscnc,jihyun-kim/heekscnc,jihyun-kim/heekscnc,satovey/heekscnc,satovey/heekscnc,jihyun-kim/heekscnc,jihyun-kim/heekscnc