"yarp namespace" command should have a scriptable option

[drdanz]

trafficstars

Running yarp namespace with no arguments prints

YARP namespace: /root

It would be useful to have a command that prints just

/root

in order to use it in scripts, for example

yarp wait $(yarp namespace)

[randaz81]

One issue is that you may have multiple active namespace e.g. yarp namespace /aaa /bbb and I'm not sure about how this should be handled.