Make it possible to create the lxc templates without a running environment

[Tim Penhey]

There is a juju-local plugin that has been added to the codebase as a skeleton, but it has no real commands yet.

One of the first commands we want is to be able to create the template containers that are used by the local provider to clone from. One of the current problems is that the first container within an environment causes the template to be created with very little feedback, this leads people to kill it, which unfortunately leaves a lock file on disk, which means the next juju environment waits forever.

Something like:

   juju local create-template precise

This would then create the juju-precise-template lxc container.

The code to create the template is found at:

  container/lxc/clonetemplate.go

The log tailer, which the EnsureCloneTemplate uses, writes the cloud-init output to the "juju.container.lxc" logger module as TRACE. The command should (I think) actually output that trace info.

This could be done by adding a custom writer and only catch the TRACE output for that module. This way the user gets feedback about what is actually going on.