remove threadpool

Change-Id: I64c4619384102abaa9c0b9bf40f9ae7a86780dd3
clock: fix typedefs for better boost integration

Change-Id: I70c375ea17787b90e9e2c7604fe7e6afe127528e
Reviewed-on: http://gerrit.aldebaran.lan/43360
Reviewed-by: cgestes <gestes@aldebaran-robotics.com>
Reviewed-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Tested-by: pdaouadi <pdaouadi@aldebaran-robotics.com>