name magic for DescriptorUnit selection

I realy do want the Ark to be easy to use--it should "just work". And the hope here is that DescriptorUnits have enought potential power that this is doable.

Now we really don't want a user assigning DescriptorUnits to the Topics they create--that's exposing too much complexity. One thought then is to assign DescriptorUnits when a Topic is created based on its name. This can be controled via an LSec Table in the DescriptorUnit of the parent Topic.

The LSec would have two columns, TopicName and DescriptorUnit, where the TopicName column contains a regex and the DescriptorUnit column would name a DescriptorUnit.

The cr_ command would then match the name of the new topic to determine the DescriptorUnit.

Hmm. A third column, Role, could also be used to restrict creation to a particular group of users for a given topic name pattern.