Permit @Name on constructors and add attribute to @Class to record whether
it has constructors.
Add metamodel for Constructors

This reverts commit 998ef953d74752bfc631871bfce24d53486d9b4c.
Version where Constructor is not a Model, and ConstructorDeclaration is not a NestableDeclaration, introducing some new interfaces (Functional, Bindable, Contained, Declared)
Make Applicable satisfy Callable adding a type parameter for the arguments, defaulted to Nothing.
Rejig the metamodel for constructors some more
ConstructorDeclaration, and some of the ConstructorModel, but not implemented constructor calling or apply() yet.
tests for ConstructorDeclarations
Bulk of implementation of Constructor metamodel
Tests for constructor metamodels
Fix non-shared class member class constructors
Fix non-shared class member class constructors: tests#
Get more stuff working
Start wrting tests for metamodels of constructors of member classes of interfaces
Return type of instantiator
Disable JS build for now
REVERT ME: Dodgy changes for handling static members.
Add constructors to JS build file, new OpenClass members #583
Placeholders for new members of OpenClass #583
Contained, Functional, Qualified #583
Implement constructor declaration in JS #583