GRBL Mega (bdurbrow rev.) DRO case/box

Hi,

This is a case for separate DRO, that you can make with bdurbrow revision of GRBL Mega.

Updated version - with additional space for DE-15, buttons and knobs (LCD cover and keyboard frame did not change, box and keyboard cover has to be print again).

It should fit with:
- RepRap Discount Smart Controller LCD
- 4x4 matrix keypad
- 60mm MPG handwheel
- DB25 and DE-15 brakeout board
- 3 push buttons and 3 5kOhm potentiometers

https://github.com/bdurbrow/grbl-Mega/