Make "jake clean" and "jake distclean" check deleted directory existence
Make "jake clean" and "jake distclean" check deleted directory existence

Closes GH-52.

jlturner/pegjs,luisvt/pegjs,crguezl/pegjs,mcanthony/pegjs,wwall/pegjs-fn,pegjs/pegjs,GerHobbelt/pegjs,mcanthony/pegjs,luisvt/pegjs,Mingun/pegjs,jlturner/pegjs,Sciumo/pegjs,crguezl/pegjs,pegjs/pegjs,Mingun/pegjs,Sciumo/pegjs,GerHobbelt/pegjs,wwall/pegjs-fn