Code review comment for lp:~wallyworld/juju-core/instance-type-constraint

Reviewers: mp+216244_code.launchpad.net,

Message:
Please take a look.

Description:
Add constraints validation to providers

Each provider has a constraints validator which
is used when setting constraints on a machine or
service, as well as when constraints are merged.
The validation step allows conflicting constraints
like instance-type and mem to be rejected, and also
unsupported constraints to be logged with a warning.
The merge step allows things like instance-type to
mask other incompatible constraints like mem or arch,
and visa versa.

https://code.launchpad.net/~wallyworld/juju-core/instance-type-constraint/+merge/216244

Requires:
https://code.launchpad.net/~wallyworld/juju-core/constraints-validation-merge/+merge/215807

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/88780043/

Affected files (+529, -61 lines):
   A [revision details]
   M environs/instances/image.go
   M environs/interface.go
   M environs/statepolicy.go
   M provider/azure/environ.go
   M provider/azure/environ_test.go
   M provider/dummy/environs.go
   M provider/ec2/ec2.go
   M provider/ec2/local_test.go
   M provider/joyent/environ_instance.go
   M provider/joyent/local_test.go
   M provider/local/environ.go
   M provider/local/environ_test.go
   M provider/maas/environ.go
   M provider/maas/environ_test.go
   M provider/manual/environ.go
   M provider/manual/environ_test.go
   M provider/openstack/local_test.go
   M provider/openstack/provider.go
   M state/addmachine.go
   M state/conn_test.go
   M state/constraints.go
   A state/constraintsvalidation_test.go
   M state/export_test.go
   M state/machine.go
   M state/machine_test.go
   M state/policy.go
   M state/service.go
   M state/service_test.go
   M state/state_test.go