state/apiserver/common: refactor AuthAlways

This branch prepares for an upcoming change to make AuthAlways more strict by splitting AuthAlways(true/false) into two helpers, AuthAlways and AuthNever which take no arguements.

As the value passed to AuthAlways was a constant in all but one case this has made the code easier to read in the common case.
sentences end with a full stop.
Merge pull request #531 from davecheney/175-state-apiserver-common-cleanup-authalways-authnever

state/apiserver/common: refactor AuthAlways

This branch prepares for an upcoming change to make AuthAlways more strict by splitting `AuthAlways(true/false)` into two helpers, `AuthAlways` and `AuthNever` which take no arguments.

As the value passed to `AuthAlways`was a constant in all but one case this has made the code easier to read in the common case.