Now adding function labels for all functions to allow fail to refer to functions in the surrounding scope (including with nesting), resolves #416
Now performing a looser check on subtyping for function types during instantiation, just making sure each individual return type and parameter type is comparable between the parameterized type and the actual type, and subtyping problems will still be determined once the type has been instantiated; resolves #409
Merge branches 'master' and 'muAnd-muOr' of https://github.com/cwi-swat/rascal into muAnd-muOr