Added G70, G71, G90 and G91 to the RS274 interpretation.
Added G70, G71, G90 and G91 to the RS274 interpretation.

haiqiangwang/heekscad,satovey/heekscad,Funcan/heekscad,haiqiangwang/heekscad,satovey/heekscad,satovey/heekscad,haiqiangwang/heekscad,Funcan/heekscad,Funcan/heekscad,Funcan/heekscad,haiqiangwang/heekscad,satovey/heekscad