How to keep track of features in grpc nodejs that are not implemented yet

[tbetbetbe]

The latest version (0.4.0) of dorusu-js is missing features that grpc-nodejs provides.

This is a meta issue that describes how to keep track of the missing features

Tracking missing features

For each missing feature

• there should be an issue tagged with label 'implementation gap'
• the issue's initial comment should simply describe the missing feature, follow-up comments should propose the implementation.
• the issue should mention this meta issue, so by looking at the mentions of this issue it's possible to see the state of the all the missing features
• if the description has enough detail, the initial comment should just mention this issue