Update lib.d.ts to more contain IE11 era APIs

Also includes ES6 Map, Set, WeakMap and ECMA402 i18n API.
Merge branch 'release-0.9.1' into develop
If the host returns a 'null' text change range, that means "treat the entire file as changed".
Remove comments from the built compiler
Adding tree/text invariant checker.

Note: this will be diabled in the next checkin for perf reasons.
Disable invariants checker.
Fix AST equivalence checks to handle NaN values for integer literals.
Remove comment.
Make error messages more consistent.