shapefile cmd truncates non-shapefile extensions from path

[anoved]

It should only do that if the extension is .shp, .shx, or .dbf; otherwise, anything that looks like an extension in the path should be treated as part of the base filename.

[anoved]

This is a consequence of how Shapelib works: name wrangling is performed in dbfopen and shpopen. Another prospective patch to submit. Until then, just be advised not to provide paths to the [shapefile] command that contain dots in the final filename, or else they'll be clipped.