Fix initial centering of canvas in real env.

Fix initial centering of canvas in real env.

In a real environment with positioned services, this centers the services within the viewport, an artifact that was lost in a recent refactor.  Also tests that the panToPoint event was fired when a positioned service is added (future designs will complicate this, as the inspector will have an arrow pointing to a service, if it's open; this will be prevented in app/views/topology/service.js:panToCenter() once that's implemented).  Other tests in place already test finding and setting the centroid.

https://code.launchpad.net/~makyo/juju-gui/center/+merge/191681

(do not edit description out of merge proposal)

[matthew.scott, 2013-10-17 17:08:19]

Please take a look.

[matthew.scott, 2013-10-17 20:30:41]

*** Submitted:

Fix initial centering of canvas in real env.

In a real environment with positioned services, this centers the services within
the viewport, an artifact that was lost in a recent refactor.  Also tests that
the panToPoint event was fired when a positioned service is added (future
designs will complicate this, as the inspector will have an arrow pointing to a
service, if it's open; this will be prevented in
app/views/topology/service.js:panToCenter() once that's implemented).  Other
tests in place already test finding and setting the centroid.

R=
CC=
https://codereview.appspot.com/14771044