cashe the nerd list for a day to reduce api calls
add promise.js
swap microajax in for promise

Smaller and does just as much for me right now; if I need promises,
add promise back in!
start using microajax for my ajax request
remove reqwest (more power than I need!)
strip any filename ending for id field

pngs are no better than jpgs!
don't show nerds that only have the placeholder image
minor refactor
split functionality into small files

I'm really trying to clean things up as much as I can. I know there is
still lots to do, like using require.js and putting these things in
modules, but this is a start.
add some functions to provide subsets of nerds

It'll be good to be able to find all the nerds with pictures, for
example.
only show unknown nerds for quiz
update database when a nerd is known; show running count
typo!!!
style nerd count footer