External module conformance tests
External module reference resolution should be predictable, and should pick .ts file if exists over .d.ts file
added browser version of tsc
addressed CR feedback
Property initializers evaluated in the scope of constructor
Two members are considered identical when
•	they are public properties with identical names, optionality, and types,
•	they are private properties originating in the same declaration and having identical types,
Fix the assert in emitting source map for function property assignment
Fix the export import in external modules
Fix the module name collision detection such that it looks deeper than just a single level
Fix the codegen when enum member conflicts with module/enum name
When a generic interface has multiple declarations, all declarations must have identical type parameter lists
i.e. identical type parameter names with identical constraints in identical order.
added webhost/*.d.ts to .gitignore
Fix emitting sourcemap baselines