The fastd_mesh_vpn site.conf section is renamed to mesh_vpn.fastd.

In preparation for Babel support.

This was causing "recursive dependency" errors and potentially broken
configurations.

gluon-announced and gluon-announce are merged to gluon-respondd.

The Gluon-specific functions of the gluon-simple-tc package are moved to
gluon-mesh-vpn-fastd.

This will require site.mk to explicitly pull in the gluon-setup-mode and
gluon-config-mode-core packages.

Better configure these properly.