Added "standard library" functions
Now I try to evaluate the function first in execution calls; there was a bug with an unrecognized argument taking precedence and entering an infinite loop
Whoops
Fixed tests to expect ints instead of int64s
Merge pull request #7 from ComputerDruid/variadic-subtract

subtract: accept variable number of arguments
Fixed int(0) (wut)
Added support for string literals!
Elements in list literals are now evaluated off-the-bat for purposes of failing fast
Added balanced paren verification
Accidentally committed a binary last time. This change brings isBalanced as well as better documentation
Removed the binary
Refactored
Fixed unnecessary evaluation of things being defined in an environment
test: update names of standard functions
test: recover from panics in test cases