Simplified Team Battle moderator interface

Team Battle's moderator interface was simplified, making it easier to create and edit questions, as well as create & edit teams.

Creating and editing questions	Managing teams

Updated documentation on Team Battle can be found here:

• Creating, editing, and removing questions in Team Battle.
• Managing teams in Team Battle.

QR code now fades out when polls lock on live content polling slides

On live content polling slides that contain QR codes, the QR code will now fade out and disappear when the poll becomes locked. This change helps make it clear that the poll is no longer available for voting.

Miscellaneous changes and bug fixes

• Session QR code download filenames from Manage Sessions now includes date & location (if configured for sessions).
• Fixed bug when creating or editing sessions, where a session name would inadvertently encode ampersands to be "&".