Updated git submodules

Updated git submodules

Project: netvirt master ac601a730179e0d6690e73457207725c37e91f7b

Remove Ipv6ServiceUtils static instance

Make it a proper singleton. Also some of the conversion and
calculation methods are true utilities and thus were made static
to avoid having to inject it.

Change-Id: If96656895c5150024ab5b9d56fc3fed8ce26ba89
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>
Make ipv6service-impl classes thread-safe

IfMgr, VirtualPort, VirtualRouter et al contain fields and Maps that aren't
synchronized. Make mutable fields volatile and use ConcurrentMaps.

Also Ipv6TimerWheel is only used by IfMgr so create a local instance instead
of a static instance and close it properly.

Change-Id: I2fef4df14a4efa5d65984040b40deade9d71bfe7
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>