gungame.lua and utsfx.lua are based off of the scripts provided with CS2D in the
sys/lua/samples directory.

Notice that both of those scripts make changes to pl.kills and use the same name
for hook functions, but they don't overwrite each other. This is because they
are using local functions and local copies of the players table.

boost.lua is using the global `players` table. this is because it doesn't need
to store any player data, so there's no need to use a local one
