Added GPL licensing information to lisp files
Fixed problem finding the default priced file.

Bug fix to detect badly specified priced files on the command line didn't handle the default correctly.
Merge pull request #137 from enderw88/default-pricedb-bug

Fixed problem finding the default priced file.
Merge pull request #138 from enderw88/ledger-mode-licensing-and-comments

Added GPL licensing information to lisp files