Code review comment for lp://staging/~dimitern/juju-core/050-api-bulk-ops-units-2

Reviewers: mp+166766_code.launchpad.net,

Message:
Please take a look.

Description:
state/api: Bulk unit operations; internal tests

This introduces srvUnits as an entry point for
bulk API operations on units, as agreed.
srvUnit is removed and the client-side API was
refactored to use the bulk operations instead.

Also added much needed internal API server tests.

https://code.launchpad.net/~dimitern/juju-core/050-api-bulk-ops-units-2/+merge/166766

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/9797046/

Affected files:
   A [revision details]
   M state/api/params/params.go
   M state/api/unit.go
   M state/apiserver/api_test.go
   M state/apiserver/apierror.go
   M state/apiserver/apiserver.go
   M state/apiserver/export_test.go
   A state/apiserver/internal_test.go
   M state/apiserver/login_test.go
   M state/apiserver/perm_test.go
   M state/apiserver/root.go
   D state/apiserver/unit.go
   M state/apiserver/unit_test.go
   A state/apiserver/units.go
   M state/apiserver/utils.go