Prints result after all specs are ran

This adds a special function called 'on-exit' that can be used to define a block
that is always the last thing to be ran.
Adds Compare() method to VList
Adds some specifications for vodka

They are definitely not the definitive spec for the language, and miss out a
bunch of stuff, but there is now _something_.

Not sure about the approach of baking in the spec "framework", as with
everything else ... it will likely change when I think of something better.
Added simple integer ranges

In short, 1..5 is a range from 1 to 5 (inclusive). Some additional functions
have been added to work with them: 'max', 'min' and 'list' converts a range into
a list, i.e. '1..5 list => (1 2 3 4 5)'.