* Makefile.in: Link cygcheck with libwininet.a.

* Makefile.in: Link cygcheck with libwininet.a.
* cygcheck.cc: Add includes.
(grep_packages): New global variable.
(display_internet_error): New function.
(safe_chars): New global variable.
(base_url): Ditto.
(package_grep): New function.
(usage): Reword --help output for clarity.  Document new argument.
(longopts): Add 'package-query' option.
(opts): Add 'p' option, reorder to be consistent with 'longopts'.
(main): Accommodate new option.
* utils.sgml (cygcheck): Update --help output.  Document new -p option.