added .gitignore file

to ignore *.py[cod] and *.log files.
support for adinebook.com and ISBNs

# support for ISBN input
# support for adinebook.com
# improved debugger messages (now stack is added to log)
# updated langid.py module (thanks to Marco Lui for his great work)

miscellaneous:
# updated related html messages
# added class Name to converter.py to be used in other modules,
    some parts of code were rewritten based on this change
# renamed citation.py to fawikicite.py
# renamed reference.py to fawikiref.py
# renamed converter.py to convertors.py