Implements #129, pam and nsswitch daemon capability. This is stage 1, which adds a localhost unix domain socket resolver, a ssh key client, support to the server for generating unix tokens, an async client lib, and client handles for adding posix extensions to accounts and groups.
Implements #134 Client Builder Pattern. This makes it much easier to build a client by making the configuration of the client lib follow a builder pattern. The error management needs a lot of work still, but for now it's rough and it works.
This adds rest endpoints for schema, group, account listing and individual item getting, client lib to call these end points, and tests for all of these.
