Parameterized Socket Rail with dovetail

This is a remix of spiridios's customizable socket rail, thanks for the excellent design!

I have added a few options to provide:

1. dovetail to help connecting multiple short rail into a long one
2. screw mounting hole instead of hanger, in case you wish to mount it onto tool wall or drawer.
3. Add side mount option, to allow the rail to mount in shallow drawers and have the sockets pointing sideway.

Both the dovetail and screw hole have some option to allow you to customize to fit y