WS-155 exclude generated files in export folder

There are several "plugins" that generate files in the export
folder that should be excluded from the ProjectFolderConfiguration.

There was code that looked like it was trying to exclude them from
the entire repo, but it seems to only attempt to exclude them from
the root directory.  These patterns were made explicit.
wouldn't a single pattern "export/*.*"  (or even "export/*") be enough (and appropriate?)  and then leave the existing patterns in place in case those files had been misplaced by antique code or something?  ie, just changing line 26 by changing "*.lift" to "*.*" (or "*").