gnetlist-legacy: Move some options back to "gnetlistrc"
Some gnetlist configuration options were previously moved to geda.conf
in preparation to a planned configuration system change:
unnamed-netname -> default-net-name
unnamed-busname -> default-bus-name
hierarchy-traversal -> traverse-hierarchy
net-naming-priority -> net-naming-priority
Move these options back to gnetlistrc in order to be consistent with
the remaining options and the current version of gnetlist.
This reverts commit
18f64a9810ec99250b45c3a29edae04b080a8a8f.