Auto-detect/display UTF-8 encoded extended file descriptions

I noticed that the recent NASA "Earth Science Picture of the Day" files have had a DIZ with UTF-8 encoded apostrophe in it. <sigh>

src/sbbs3/file.cpp

@@ -101,7 +101,7 @@ void sbbs_t::showfileinfo(file_t* f, bool show_extdesc)
 		char* p = f->extdesc;
 		SKIP_CRLF(p);
 		truncsp(p);
-		putmsg(p, P_NOATCODES | P_CPM_EOF);
+		putmsg(p, P_NOATCODES | P_CPM_EOF | P_AUTO_UTF8);
 		newline();
 	}
 	if(f->size == -1) {

src/sbbs3/listfile.cpp

@@ -437,7 +437,7 @@ bool sbbs_t::listfile(file_t* f, uint dirnum, const char *search, const char let
 			|| strnicmp(ext, "\0010", 2) == 0
 			|| strnicmp(ext, "\001W", 2) == 0)
 			ext += 2;
-		putmsg(ext, P_INDENT | P_NOATCODES | P_CPM_EOF | P_TRUNCATE);
+		putmsg(ext, P_INDENT | P_NOATCODES | P_CPM_EOF | P_TRUNCATE | P_AUTO_UTF8);
 	}
 	return true;
 }