BOM dialog: remove a not very useful button, and merge its function with an other (not perfect, need more work)
Add message box to show info added in BOM python scripts (See scripts/bom-in-python/README-bom.txt about this info)

fix also a bug in python script round_value_robin.py.

fix also a bug in python script round_value_robin.py.

Significantly enhance the bom_csv_grouped_by_value.py BOM generator.
IMO it at this moment, the best BOM production tool for KiCad.

   File "rules" has instructional text as comments near top.

2) Convert all text files in repo to LF line ending form.
   Any checkout done with "rules" in play will convert the working
   tree to native line ending, while keeping repo as LF line ending.