'Freeze' state should be saved with ows

[irgolic]

Currently, to open a workflow in a frozen state, you first need to press 'Freeze' (the pause button next to the help button in the toolbox), then load the workflow.

This should be saved in the workflow file itself.

Also, it seems the way it works is, if you open a workflow frozen, the widget's aren't created yet. Flicking 'freeze' on and off real quick doesn't propagate the changes, but then allows you to open all the widget windows.
'Freeze' should probably only halt signal propagation, not also widget creation.