* cygcheck.cc (find_package,list_package): New global
variables.
(usage): Add "--find-package" and "--list-package" options,
reformat output.
(longopts, opts): Add "--find-package" and "--list-package"
options.
(main): Process the "--find-package" and "--list-package"
flags. Add new semantic checks. Add calls to find_package()
and list_package().
* dump_setup.cc: Fix header comment.
(match_argv): Change return type to int to distinguish
between real matches and default ones.
(open_package_list): New static function.
(check_package_files): Factor out opening the package list
file into open_package_list().
(get_packages): New static function.
(dump_setup): Factor out getting a list of packages into
get_packages().
(package_list, package_find): New global functions.