Ensure consistent library version across different files.

https://code.google.com/p/esprima/issues/detail?id=470
Use ESLint to lint the code.

https://code.google.com/p/esprima/issues/detail?id=473
Use single-quoted string literals.

https://code.google.com/p/esprima/issues/detail?id=398
ESLint should tolerate assignment to a function.

Until this harmony branch doesn't use the tracker wrapper approach,
we still need to allow assignment to/from a function.

https://code.google.com/p/esprima/issues/detail?id=473
Fix ESLint errors: trailing comma and non-camel case ids.

https://code.google.com/p/esprima/issues/detail?id=473