- added support for string constants to unparse()

- implemented eval_str
- expand() now tries to obtain a string
- added example fbga.fpd to demonstrate use of strings
- when invoked with an inexisting file, fped now starts with an empty model,
  instead of getting confused 
- we now religiously call edit_nothing before adding fields to edit, so that
  we won't create a loop through edit-next



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5421 99fdad57-331a-0410-800a-d7fa5415bdb3

fped.c

@@ -32,8 +32,12 @@ char *save_file_name = NULL;
 
 static void load_file(const char *name)
 {
-	reporter = report_parse_error;
-	run_cpp_on_file(name);
+	if (file_exists(name) == 1) {
+		reporter = report_parse_error;
+		run_cpp_on_file(name);
+	} else {
+		scan_empty();
+	}
 	(void) yyparse();
 }