Feb. 16, 2010: Vocaboly 3.0

1. Lesson support - Now you can easily define lessons when create new books.
2. Create a new book without using book source file.
3. Add new words to exiting books.
4. Besides a word's definitions, the word itself can be modified as well. Combined 2, 3 and 4, a book basically can be edited freely.
5. Generate a new book from current word list.
6. Generate book source file from current word list. 5 and 6 make it very easy to create a new book based on one or more existing books.
7. Automatic backup when saving a book.
8. Replace sound effects with word pronunciations in tests and games to improve listening experience.
9. Other small changes.