add defaults to switch statements to silence warnings

i hate c

unflip x and y

add width and height operators

add exponentiation

add gitignore

unswap s and d in the readme

update usage

update readme

add logical not

add -i switch

add option for color

output to stdout by default

add left&right shift

make division by zero error apply to mod as well

add dup and swap

add eq lt gt and count

add gradient mode

require -o

add error handling on division by zero