add ex50(python2 only)
create basic templates
change the greeting variable and the template HTML
using web.input to get data from the browser
get two parameter on the URL
set greet default to None so that to check if it exists and give a better error message
add a link back to /hello
create a layout template
give a better layout and beautify the style(thanks to the amazing twitter-bootstrap!)
add a upload form to upload and view image.
avoid the user from clicking the submit button without chooing a file
add ex49
write a test
change the parser_ methods and put them into a class
make the parser more error-resistant; improve the way of calling assert_raises function
Several improvements

- Place exercises after ex47 into one project named games
- Improve the grammar by handling more things like numbers
- Extend the lexicon to handle plural and singular nouns