Gateway should start even without all services running

[PaulBredl]

It would be useful if the gateway could start even without all services.
I don't know its exact capabilities, but it would be great if the gateway could just cache the schema.
This is also an improvement to reliability, as in a real-world scenario, not every service is always available.

[myluki2000]

The gateway needs the services' schemas to construct its stitched-together schema. It is possible to provide local (cached) schema files for each service in the gateway's .meshrc config file. When the schema becomes more stable this would make a lot of sense. Currently, however, I'm not sure if this wouldn't cause more headaches than it's worth because you'd need to make sure to keep these cached versions up to date, otherwise the gateway's schema will be messed up.