Added MSG_IMP_DATE and MSG_IMP_TIMEZONE codes (message imported date/time

and timezone), for Mark Lewis.
The imported timezone will always be the local timezone (at the time of import)
so not sure what value that has. <shrug>

src/sbbs3/atcodes.cpp

@@ -1215,11 +1215,15 @@ const char* sbbs_t::atcode(char* sp, char* str, size_t maxlen, long* pmode)
 		return(current_msg->tags==NULL ? nulstr : current_msg->tags);
 	if(!strcmp(sp,"MSG_DATE") && current_msg!=NULL)
 		return(timestr(current_msg->hdr.when_written.time));
+	if(!strcmp(sp,"MSG_IMP_DATE") && current_msg!=NULL)
+		return(timestr(current_msg->hdr.when_imported.time));
 	if(!strcmp(sp,"MSG_AGE") && current_msg!=NULL)
 		return age_of_posted_item(str, maxlen
 			, current_msg->hdr.when_written.time - (smb_tzutc(current_msg->hdr.when_written.zone) * 60));
 	if(!strcmp(sp,"MSG_TIMEZONE") && current_msg!=NULL)
 		return(smb_zonestr(current_msg->hdr.when_written.zone,NULL));
+	if(!strcmp(sp,"MSG_IMP_TIMEZONE") && current_msg!=NULL)
+		return(smb_zonestr(current_msg->hdr.when_imported.zone,NULL));
 	if(!strcmp(sp,"MSG_ATTR") && current_msg!=NULL) {
 		uint16_t attr = current_msg->hdr.attr;
 		uint16_t poll = attr&MSG_POLL_VOTE_MASK;