Parametric Pipe Fastener

A parametric version of the Pipe fastener (https://www.thingiverse.com/thing:347760). Enables a flush seamless connection of two pipes / conduits.

- Added the possibility to easily change the bolt size (included M-size bolts M1-M24), pipe diameter, wall thickness and part height.
- Added bound checks to cut out infeasible values.
- The diagonal part now changes its angle if the part's height is too small.
- The nut is embedded into the bottom of the part.
- Fixed the wall thickness issue.
- Translated from german to english, and added comments.