Remove std::regex from CommsBrokerPlugin

[caguero]

std::regex is painfully slow and causes a very slow callback in OnPose() processing Ignition poses. This is generating a huge queue of incoming messages and a major delay processing them.

How to test?

Replace the for loop in CommsBrokerPlugin.cc::OnPose() with this one:

// Update all the published poses
for (int i = 0; i < _msg.pose_size(); ++i)
{
  this->poses[_msg.pose(i).name()] = ignition::msgs::Convert(_msg.pose(i));
  if (_msg.pose(i).name() == "X1")
    std::cout << "X1 pose: " << this->poses[_msg.pose(i).name()] << std::endl;
}

Now launch your world:

ign launch cave_circuit.ign worldName:=cave_circuit_practice_02 robotName1:=X1 robotConfig1:=X1_SENSOR_CONFIG_1

And teleoperate your robot:

roslaunch subt_example teleop.launch

Without this patch you should observe that changes in the position of your robot take a while until are noticed by the callback. This issue should be fixed with this patch.