Duplicated Workbench Moderation State widgets on node forms

The oa_workbench_moderation_state pane tries to remove the workbench_moderation_state_new field from existing node forms and stick it in a dedicated pane. This works if that pane loads before the "publishing options" pane. But in some cases (I haven't been able to tell exactly how/why it happens), the oa_workbench_moderation_state pane is built AFTER the node_form_publishing pane, meaning that it's trying to remove an element from the form too late, which leads to that element being duplicated. Screenshot: http://note.io/1LeGu7K

A quick fix for this is to make oa_workbench_moderation_state only do the replacement if #access hasn't already been set to FALSE for that form element (which is what the node_form_publishing does when it's building). This at least makes oa_workbench smart enough to say "oops, I'm too late to unset that field, so I'll just avoid adding my own".

Patch incoming.