Updated parametric wall holder for remote control

Updated parametric holder of egil's model.

Features added:
- mounting screw holes can be switch off for mounting with double sided tape
- the corners of the cut-out section can be cut off (or not) to make inserting the remote easier
- the detail of the render can be chosen. (higher quality at the cost of render time)

I modified it to learn/understand OpenSCAD a bit better and I hope this update is useful for others.

If anyone has an idea how to round of the sharp edges of the cutout, please let me know in the comments.