more objectish things
Merge pull request #9 from AlexKnauth/thing

more objectish things
Fixed (select case ...)
Implemented 'with' literal for loops

``do`` and ``for`` loops can now initialize cry by using the ``with``
keyword.

(for (x in lst with 5) ...) for example will initialize cry with the
value 5, rather than the default null list. Similarly you can do (do
loop with 5 ...) for the similar effect.
Added (mod x y)

Returns the modulus of x and y. Undecided as to correct name for
remainder function.
(macro id . stuff) -> (macro-id . stuff)