tailq: introduce dynamic register system

This register system makes it possible to reserve a tailq for the dpdk
libraries.
The "dynamic" tailqs are right after the "static" tailqs in shared mem.
Primary process is responsible for writing the tailq names, so that secondary
processes can find them.

This is a temp commit, "static" tailqs are removed after conversion of all
users in next commits.

Signed-off-by: David Marchand <david.marchand@6wind.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>