Added tests/baselines.
Fixed issue where the second type's signature having type parameters would not cause an error.
Undid comment change that made things more misleading.
Merge pull request #1533 from Microsoft/fixCompareSignatures

Fix compareSignatures
Enable incremental parsing by default.
Merge pull request #1568 from Microsoft/enableIncremental

Enable incremental parsing by default.
Add -symbolForPrivates compiler flag.
Emit one __symbol function declaration per file.
Change emitMemberAccessForPropertyName to take in the whole member declaration.
Add functions to get whether a property access is for a private property or a static property.
Use Symbol for private members.