remove explicit dep. pattern matching, trying with eliminators
start with the sugar
more distilling
REPL stub
oops
re-oops
oops
group equal parameters
got rid of garbage
Type : Type, impredicativity yo
explicit type signatures for datacons
typecheck type constructors
more liberal parsing
elaborate datacon types
fix two elaboration bugs

`freeVs' didn't actually work - it didn't return free things under
binders.

I was forming the datacon types wrongly.
fix uniquify
forgot to add files...
tweak parser
elaborating, set up infrastructure for eliminators
generate constructors