Allow to init the runtime using napi_register_module_v1 #30

For embedding NativeScript in React Native using https://github.com/callstackincubator/react-native-node-api we need to add support for initializing the runtime with napi_register_module_v1.

• Add a build flag to build the runtime as a napi module
• Disable parts of runtime code that are unrelated or might cause issues when running as a module
• Update to Hermes V1 if possible