Bb Doc Viewer+ per Raj Kundu

This extension makes the following improvements to Blackboard:
- Adds 'Open in New Tab' button to Bb-embedded document viewers
- Allows use of the Escape key to close Bb panels
- Automatically maximizes Bb files opened in a new window/tab
- Sets page title to document filename

NOTE: This work is UNOFFICIAL, and neither it nor its contributor(s) are related to Blackboard, Inc. in any official capacity. Blackboard and Bb are trademarks of Blackboard, Inc.