b2/: move parts dumping from lang.y to boom.c and make optional (-dc)

b2/boom.c

@@ -87,6 +87,9 @@ static void dump(const char *s)
 {
 	while (*s) {
 		switch (*s) {
+		case 'c':
+			parts_dump(stderr);
+			break;
 		case 'h':
 			dump_hierarchy(hierarchy);
 			break;

b2/lang.y

@@ -418,7 +418,6 @@ characteristics:
 	| part characteristics
 		{
 			part_finalize($1, &hierarchy);
-			part_dump(stderr, $1);
 		}
 	;