. Added add_mime_mapping() to add to mime_map in unsorted order.
. Added sort_mime_map() - uses qsort() and mime_mapping_cmp() to sort
the mime_map.
. uri_content_type() uses bsearch() and mime_mapping_cmp_str() to search
through the mime_map for an extension parsed out of a specified URI.
. Free mime_map in exit_quickly()
. Completely deallocate connlist in exit_quickly()
. In main(), parse_commandline() after parse_default_extension_map() so
that a specified --mimetypes file will -override- the defaults.