Move the HST namespace to 2.1

I want to sort out how a customer that is on the HST 2.0 namespace which is a little different than the one from the HST2 trunk can upgrade.

I think there are some incompatible changes, thus a reload cannot work. Furthermore, their actual configuration (the created nodes) as it currently is, is compatible with the trunk cnd. Because I think we cannot 'remove' a namespace and register the new one, we most likely are best off when bumping the current ns version, register this one, and switch to this one during upgrade.

Right?