moved trig functions from shell into phys namespace
changed namespace phys to physics
refactored main.js to hide more queue-specific stuff in Worlds
Merge branch 'frontend'
fixed bugs in World refactoring, in main.js
fixed merge conflict
added new shooter program; commented out because writing to SHOT not working
Merge branch 'master' into shell
Merge branch 'shell'
added tick-shell function
added support for shells to tick-combined-world
changed shell constants
removed comment in shooter source code
altered shooter source code to not use random numbers
got shells (mostly) working