- 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