state: Introducing StringsWatcher interface

state: Introducing StringsWatcher interface

Replaces LifecycleWatcher, MinUnitsWatcher, UnitsWatcher,
and MachineUnitsWatcher (all of these are now unexported
and the creation functions return the interface instead).
It defines a common patterns for a watcher returning
changes as []string.

This is a preliminary step towards implementing some
of the API needed by the deployer.

https://code.launchpad.net/~dimitern/juju-core/065-state-stringswatcher/+merge/173771

(do not edit description out of merge proposal)

[dimitern, 2013-07-09 16:34:08]

Please take a look.

[fwereade, 2013-07-09 16:36:51]

LGTM, but fix the name I flag below.

https://codereview.appspot.com/11044043/diff/1/state/apiserver/watcher.go
File state/apiserver/watcher.go (left):

https://codereview.appspot.com/11044043/diff/1/state/apiserver/watcher.go#old...
state/apiserver/watcher.go:57: type srvLifecycleWatcher struct {
Would be good to make this a srvStringsWatcher.

[mue, 2013-07-09 16:39:00]

LGTM

[dimitern, 2013-07-09 17:23:04]

https://codereview.appspot.com/11044043/diff/1/state/apiserver/watcher.go
File state/apiserver/watcher.go (left):

https://codereview.appspot.com/11044043/diff/1/state/apiserver/watcher.go#old...
state/apiserver/watcher.go:57: type srvLifecycleWatcher struct {
On 2013/07/09 16:36:51, fwereade wrote:
> Would be good to make this a srvStringsWatcher.

As agreed online, I'll do that in a follow-up.