Ensure proper committed status on containers.

This fixes bug https://bugs.launchpad.net/juju-gui/+bug/1369601

Containers had been (incorrectly) inheriting their commited status from
their parent machine. That meant that a newly-created container on an
existing machine would show up as committed upon re-render. We now check
for 'new' in the name of each container and set its committed status
based on that. The only exception is root containers, which still
inherit from the parent machine because they *are* the parent machine.
Merge pull request #552 from kadams54/fix-uncommitted-indicator-1369601

Ensure proper committed status on containers.

This fixes bug https://bugs.launchpad.net/juju-gui/+bug/1369601

Containers had been (incorrectly) inheriting their commited status from
their parent machine. That meant that a newly-created container on an
existing machine would show up as committed upon re-render. We now check
for 'new' in the name of each container and set its committed status
based on that. The only exception is root containers, which still
inherit from the parent machine because they *are* the parent machine.