Add crufty libsetup_setvnodeid, libsetup_getvnodeid so scripts can set
the vnode on whose behalf they are operating. The library passes this through to tmcd. Move definition of the delay_mapping file in from liblocsetup so that it is easily exportable withou another hoop. Add configuration support for veth devices. Change route and ifconfig generated script to do enable/disable segments in the generated scripts so that per-jail configurations can be added/removed easily by mkjail. Add program agents configuration, with corresponding tmcd command to return the list of program objects for a node (or jail). Trafgens inside jails talk to the local elvind, not boss. dotunnels, doroute, doiconfig all take an optional rtabid and pass that through to libloc routines. Add trivial support for getting the user shell from tmcd.