DI for nested services

[noamknispel]

According the docs & example app when you create nested service it'll be available in nested:service. This format is understandable when you call your service directly from the container but not when you need to inject it.

constructor(nested:service) { ... } // => Won't work

The suggested solution is get rid of the full path of a service, and call it by his unique name. Nested directory structure should be available only for good look and maintainability reasons.

[igorshapiro]

Duplicate of #115