tag 0.94 as first version supporting IPv6 PDP contexts

tag v0.93 for fixed GTPv1 in Linux Kernel GTP-U support

Add 'Bearer Control Mode' IE

This IE is known to be sent by a Cisco GGSN, and was added in
ETSI TS 129 060 V7.17.0 (2011-10) /
3GPP TS 29.060 version 7.17.0 Release 7

See https://lists.osmocom.org/pipermail/osmocom-net-gprs/2016-September/000711.html
Subject "sgsnemu failing to create PDP context with Cisco GGSN"
Tue Sep 13 08:00:37 UTC 2016

Tweaked-by: Neels Hofmeyr <nhofmeyr@sysmocom.de>

tag v0.92 for installing gtpie.h

tag the 0.91 release which contains the libgtp as needed by OsmoSGSN

Release openggsn v0.90