Converted service and unit views to use promises

Converted service and unit views to use promises

-Attempt at a clean diff-

In addition to converting the unit and service views
to use promises:

If the user is viewing a service and
that service is no longer available it will redirect
them to the environment with a notification.

If the user is viewing a unit and that unit is no longer
available the user will be redirected to the service.

If the user is viewing a unit and that units service
is no longer available then the user will be redirected
to the service.

https://code.launchpad.net/~hatch/juju-gui/view-promises-merge/+merge/162224

(do not edit description out of merge proposal)

[jeff.pihach, 2013-05-02 19:17:57]

Please take a look.

[jeff.pihach, 2013-05-02 19:59:30]

Please take a look.

[gary.poster, 2013-05-02 21:01:02]

looks good.  qa'ing.

https://codereview.appspot.com/9119044/diff/3001/app/app.js
File app/app.js (right):

https://codereview.appspot.com/9119044/diff/3001/app/app.js#newcode597
app/app.js:597: // or showing details but the service has become unavailable
Thanks for the clarification.  It can only be in a loading state, right?  There
should be no way we get here after the page has started showing details?  This
is only important insomuch as we want to be clear in our comment.

[gary.poster, 2013-05-02 21:22:56]

LGTM with a conflict resolution with trunk that handles the "I have no units of
that existing service" initial URL.

Thank you!

[bcsaller, 2013-05-02 21:25:46]

LGTM

There was a trivial or two in there and some forward looking notes I would like
your thoughts on though.

https://codereview.appspot.com/9119044/diff/3001/app/app.js
File app/app.js (right):

https://codereview.appspot.com/9119044/diff/3001/app/app.js#newcode519
app/app.js:519: var handle = setTimeout(function() {
I can envision a way that we can declare requirements for views and reuse this
pattern such that 

create an Array of promises for requirements
create timeout handler
Y.batch(requirementPromises)
.then(...
      cancelTimeout
      showView
)

Maybe something for the future, its a DRY violation to have to repeat this setup
pattern. 

Fine for now though.

https://codereview.appspot.com/9119044/diff/3001/app/app.js#newcode864
app/app.js:864: match = /(logout|:gui:\/(charms|service|unit))/;
I'd almost rather the routes contained metadata, like 
allowBrowser: false than trying to capture it here. The problem with this is we
work to make routes reversible from models and not staticly coded into the app.
This is a DRY violation in that we encode app urls in yet another place.

Notes for the future I guess.

https://codereview.appspot.com/9119044/diff/3001/app/app.js#newcode899
app/app.js:899: next(); return;
newline

https://codereview.appspot.com/9119044/diff/3001/app/views/service.js
File app/views/service.js (right):

https://codereview.appspot.com/9119044/diff/3001/app/views/service.js#newcode480
app/views/service.js:480: 
nice improvement