Fixed types of built-in functions.
Added creation of normalized type conjunctions and normalized type
disjunctions.
Added syntax sugar for combinators and type combinators and DatatypeDef
class.
Changed arguments of Unittype to sequence of TypeValueLambda for sugar
of datatype.
Added and modified tests for unit type and fixed some things.
Fixed typer and fixed tests and added test.
Added makeDatatypeDef.
Fixed makeDatatypeDef.