Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the

command entry structs and a couple of functions to check/set the flags.

cmd-source-file.c

@@ -37,7 +37,7 @@ struct cmd_source_file_data {
 const struct cmd_entry cmd_source_file_entry = {
 	"source-file", "source",
 	"path",
-	0, 0,
+	0, "",
 	cmd_source_file_init,
 	cmd_source_file_parse,
 	cmd_source_file_exec,