Deal with RepG G92 bug in which it insists on querying the current position when connected over USB and then setting the position.  If it gets garbage for the E position and then sets it as the position, then the later absolute move to E0 command spews out a lot of filament or makes a large filament reversal
Merge pull request #8 from jetty840/dnewman-merge

Deal with RepG G92 bug in which it insists on querying the current posit...