gpg: Remove experimental feature to export w/o user-ids.
* g10/options.h (IMPORT_DROP_UIDS, EXPORT_DROP_UIDS): Remove. * g10/import.c (parse_import_options): Remove option import-drop-uids. (import_one_real): Remove drop uids code. (remove_all_uids): Remove function. * g10/export.c (parse_export_options): Remove option export-drop-uids. (do_export_one_keyblock): Remove drop uids code.