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

Allows reconfigurtion of remote syslog from within site.conf.

Conflicts with the gluon-web-logging package as user made changes
will be overwritten, because this package will reconfigure the syslog
destination on every upgrade.

Resolves #1845