import-checker: extract function to generate a formatted warning This is the stub to embed lineno. See the next patch for details.

import-checker: make it executable for convenience

test-fileset: glob the updated file count for Windows stability Some of the prior changes are platform dependent, involving symlinks, exec bits and non portable names. An update 10 lines above also globbed this value to avoid differences, since this line isn't of particular interest- the filesets are.