Ultimate64 Power+Button Shroud improved

This is an improvement of Crashmeplease's shroud & button for the Ultimate64 v1.1 (shipped in December 2018) in original c64c or the new Pixelwizard cases (the photo without U64 inside is a Pixelwizard case!).

Things I changed:
1) Added a circular hole for the plug, so the powerplug fits nicely (extra big hole version provided for people that use a different power supply with a bigger diameter!)
2) Thinned out the wall at the bottom, so the screw hole is actually on top of the hole on the board and it actually fits in the case without force, with the board-holes aligning nicely
2a) Deepened the button hole the same width as the wall got thinned, so the button isn't permanently pressed
3) Made the shroud thicker at the button, so it's nice and level to the powerplug and case
4) Cut away at the bottom far edge of the shroud, so it fits nicely with the slope of the case at the back.
5) made the plastic thicker around the screw, so it doesn't break as easily when printed upright