Check to see if NT Subtable is in use

[AustinShalit]

Add a check to all NT publish operations to see if the subtable name is already being used by GRIP.

[JLLeitschuh]

What if you stop and start grip. Then you have to stop and start your network tables server to be able to use that table again.

[AustinShalit]

I was thinking more of two publish operations in the same pipeline.

[JLLeitschuh]

Oh, okay, sure, that makes sense.