Minimize features dependency

In mlmt project we are using odl-openflowplugin-nsf-model feature. This feature contains models, that we don't need. We should switch from using redundant bundles to using only those which we need (unfortunately there is no other feature including only inventory and topology models, so we have to use these bundles directly).

Moreover, to use this feature we prolong our build time because all openflowplugin features need to be downloaded.