* Specctra exported polygons are now closed (as required)
* export custom shape is provided in code, but not activated, because i have no way to text it
* fix Specctra export dialog (replace OK and Cancel buttons by only one Close button)
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.