Integrate QR Code scanner to read from db

[actual-saurabh]

The QR Code contains the ticket code which can be used to retreive more data and display the user's data like

• Ticket code
• Name
• Role (Speaker, Attendee)
• Discount Coupon Used (hence if ID required)
• Photograph (from email+gravatar)
• T-shirt Preference
• T-shirt Size

These can be used by the volunteer to see if the discount coupon is appropriate and valid. If the person carrying the ticket is the one in the photo. If they need special treatment (speaker). What T-shirt to give them.