Added option for graphical overlay for Z-offset (Resubmission of #7350 and #7586)

[marcio-ao]

Resubmision of #7350 and #7586.

I deleted the repo on GitHub and started fresh with a new fork. Hopefully things match up now. Third try is a charm?

[thinkyhead]

Seems solid now, thank you!

[Tannoo]

How do I correct the graphics the correct way?

The graphics overlay is only displaying about every other line. When I move the bitmap data to ultralcd.h, then all is fine. When it's in the dogm_bitmaps.h file, it's all messed up.

[thinkyhead]

There should be no difference. The #include keyword makes dogm_bitmaps.h and ultralcd.h form one big blob of text. Perhaps the way it's being drawn is inappropriate, and this only manifests under certain conditions. Compare to other code that draws to the screen.

[Roxy-3D]

.h files should not generate code. We need everything in compliance with that rule. The whole problem with the ultralcd code is the .h files generate code. That needs to be fixed.