Started to add glb to the rascal types.
Added FunctionType.glbWith<Type>(Type) and
OverloadedFunctionType.glbWith<Type>(Type), and made fixes to the lubs.
Added NonTerminalType.glbWith<Type>(Type),
ReifiedType.glbWith<Type>(Type).
Overloaded function type is not the lub of its alternatives.
Fix in subtyping of two overloaded function types.
Added rascal types as an option to the random type generator; added lub
and glb tests for the rascal types.
Merge branches 'add-glb' and 'master' of https://github.com/cwi-swat/rascal into add-glb
Commented out the println in the lub and glb tests for rascal types.
Small refactoring.
Merge branch 'add-glb'