Fix outputs validation place in Stack.validate

Because of outputs validation check located in
wrong place, outputs validation skipped, when
template has no resources. It's incorrect because
of possible incorrect references to unknown resources.

Change-Id: I693b51540b0678aa17b861b9f85a0cb2a9552660
Closes-bug: #1396441
Record update_time for suspend/resume/snapshot actions

Record update_time for stack actions: suspend/resume/snapshot

Change-Id: I04f0f64bd267998b0bc4f7c1bd47e642fb1dffe6
Closes-Bug: #1385109
Fix error msg invalid stack or res name

If template contains resource with name like
'res/name', we will get traceback instead of
correct error message. The same situation with
stack name: if it's incorrect, we will get
traceback.

Change-Id: I4a0e51ff649aaaad5f18f52383dab186dab54230
Closes-bug: #1397313
Merge "Record update_time for suspend/resume/snapshot actions"
Merge "Fix outputs validation place in Stack.validate"
Merge "Fix error msg invalid stack or res name"