Added a Separate Check For Joint Limits

[Jmeyer1292]

For the sake of efficiency, I've broken out the check for joint limits. This let's you use the following code to search redundant joints without performing redundant collision checks:

See IKFastMoveitStateAdapter's getAllIK function:

 if (!solver->getPositionIK(poses, dummy_seed, joint_results, result, options))
  {
    return false;
  }

  const auto dof = getDOF();
  const auto index6 = dof - 1;
  const auto index4 = dof - 3;

  auto search_extras = [this, &joint_poses, index6, index4](std::vector<double>& sol)
  {
    bool collision_checked = false;

    const double joint6 = sol[index6];
    const double joint4 = sol[index4];

    for (int i = -1; i <= 1; ++i)
    {
      sol[index6] = joint6 + i * 2.0 * M_PI;
      for (int j = -1; j <= 1; ++j)
      {
        sol[index4] = joint4 + j * 2.0 * M_PI;
        if (isInLimits(sol))
        {
          if (!collision_checked)
          {
            if (isInCollision(sol)) return;
            else collision_checked = true;
          }
          joint_poses.push_back(sol);
        } // in limits
      }
    }
  };

  for (auto& sol : joint_results)
  {
    search_extras(sol);
}

I need to figure out how to nicely integrate this into IKFastStateAdapter. I don't always want to search every joint that could be searched (all of them on a UR for example). How do we let users configure this?

Please take a look @BrettHemes.