Display student name/nick instead of default avatar.

[toonarmycaptain]

README.md promises student names/nicknames/avatars. This is not currently supported.

Can default avatar be overlaid with student's name/nick when using the default avatar?

This is probably best implemented as editing the default avatar with overlay, and saving that avatar for the student (to avoid regenerating unnecessarily).

[toonarmycaptain]

Might need to abbreviate name somehow to fit text readably on a 100x100 avatar. Initials?

[toonarmycaptain]

This would definitely need to be configurable, on or off, initials, scrambled initials, something, since part of point is o allow anonymous-ish display of results.