Jonathan Boulle ee522025b3 etcdserver: restructure auth.Store and auth.User
This attempts to decouple password-related functions, which previously
existed both in the Store and User structs, by splitting them out into a
separate interface, PasswordStore.  This means that they can be more
easily swapped out during testing.

This also changes the relevant tests to use mock password functions
instead of the bcrypt-backed implementations; as a result, the tests are
much faster.

Before:
```
	github.com/coreos/etcd/etcdserver/auth		31.495s
	github.com/coreos/etcd/etcdserver/etcdhttp	91.205s
```

After:
```
	github.com/coreos/etcd/etcdserver/auth		1.207s
	github.com/coreos/etcd/etcdserver/etcdhttp	1.207s
```
2015-10-30 16:33:40 -07:00
..