poor error message on fsid mis-match

[carns]

If you start two servers that don't agree on the ID setting, then they print error messages that look like this:

[E 04/02 20:16] batch_create request got: Invalid argument
[E 04/02 20:16] batch_create request got: Invalid argument
[E 04/02 20:16] batch_create request got: Invalid argument
[E 04/02 20:16] batch_create request got: Invalid argument

We should identify this problem earlier in batch create print something more informative.

Also check documentation to make sure that we are consistent in saying that the conf file should be generated in one place and then copied around.