Added debugging directives to the fped language. They're describe at the end

of README.

- fpd.l, fpd.y, README: added debugging directives %del, %move, %print, %dump,
  and %exit
- obj.h, fpd.y (find_obj, find_label, new_obj): objects can now be labeled
- obj.c (obj_anchors), inst.c (inst_anchors): gathering the list of anchors is 
  now a per-object function, not an instance "method". inst_anchors implements 
  the vector vs. object switch.
- inst.h, inst.c: removed all *_op_anchors functions
- expr.c (str_unit): in the past, we returned a malloc'ed string, but these 
  times are long gone. Thus, don't stralloc("").



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5919 99fdad57-331a-0410-800a-d7fa5415bdb3

expr.c

@@ -55,7 +55,7 @@ const char *str_unit(struct num n)
 	char buf[20]; /* @@@ plenty */
 
 	if (n.exponent == 0)
-		return stralloc("");
+		return "";
 	switch (n.type) {
 	case nt_mm:
 		unit = "mm";