The vpn-core package does not utilize simple-tc anymore.
This is now up to the VPN implementations.

Signed-off-by: David Bauer <mail@david-bauer.net>

The ip6tables-legacy metapackage was renamed to ip6ables-zz-legacy.

Require legacy iptables, as Gluon still depends on firewall3. Otherwise,
nftables is pulled in as a dependency.

This removes PKG_VERSION and PKG_RELEASE from most Makefiles, as the
value was never useful for Gluon packages; instead, PKG_VERSION is set
to 1 in gluon.mk.

It also removes two other weird definitions:

- gluon-iptables-clamp-mss-to-pmtu replicating the old PKG_VERSION logic
  from gluon-core, but without the fixed PKG_BUILD_DIR to prevent
  unnessary rebuilds
- gluon-hoodselector set GLUON_VERSION=3

With the removal of ramips-rt305x, the last user of
GLUON_SPECIALIZE_KERNEL is gone.

This is a fix for the broken ingress traffic-shaping in gluon v2018.2.2
and possibly earlier.

For ingress traffic shaping the kernel option NET_ACT_POLICE is needed.
Before this patch there was no dependency to this. Neither in
gluon_core, gluon-mesh-vpn-core nor in the package.

This patch adds this dependency.

[Matthias Schiffer: move dependency from GLUON_CORE to gluon-mesh-vpn-core]

Fixes #1790

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