Validate string arguments

From now on, esniff provides [resolve-concat](https://github.com/medikoo/esniff/blob/master/resolve-concat.js) utility, and with that we may resolve properly string concats and be sure we do not pass unverified code through eval.

So now you can validate possible string argument as `resolveConcat(string).forEach(validStringLiteral)`, and if it passes then blindly pass it through eval