(could_not_access,directory_exists): New static function.
(file_exists): Ditto.
(check_package_files): Ditto.
(dump_setup): Check the contents of each package if check_files is true and
output the result in the "Status" column. Flush output after each package.
* dump_setup.cc (dump_setup): Remove redundant null check. Add informative
message if package info not found.