renaming collection for simpler fcstd base examples

instead of using freecadlib as examples for fcstd bases, we start with
some simple profiles. These are not yet added.
fixed nonconforming basefiles
stl bases for openscad
found a proper place for check_dict
Merge branch 'master' into fcstd_base
fixed non-conform base files
fixed typo in spec
rewrote base function parts nicer

instead of having a dict of basefunctions that is loaded and kept
separately in the widgets, we now use a class to hold all the metadata
of a base function. This is similar to the way it is implemenet in the
OpenSCAD backend. The module with the function in it is only loaded on
demand.
removed unused stuff
added needle bearings
removed the two row needle bearings

I had added them accidentally
fixed a few typos and added missing field
fixed a few path problems and smaller stuff

fcstd base is inactive, because the copying of objects is not done
properly yet.
added BOLTS profiles metadata and files

not yet functional, because the fcstd base does not work
copying objects from Fcstd bases now works
changed object identification to object name

vrail models are not a pad, and only pads are working right now, so I
removed them.