--follow-neurons parsing error

[timohanke]

When --follow-neurons is the last argument, only followed by <NEURON_ID> of the neuron that is being managed, then the command line parser seems to interpret <NEURON_ID> as just another followee and complains that <NEURON_ID> is missing.

A work-around is to put --follow-topic between the followees and <NEURON_ID>.