gmoccapy_0_9_9_9_7 - highlight gcode line by grafics click

ver. 0.9.9.9.7
- add gcode highlight by clicking in the preview
  clicking a line in the preview will highlight the
  corresponding line in gcode listing
gmoccapy_0_9_9_9_8 - corrected hardware switch behavior

ver. 0.9.9.9.8
- toggle button setup was not handled correct by hardware
  momentary switches, fixed that