Update CTaskBase (remove non-generic functions)

[Samir Menon]

This code seems superfluous..

  /* **************************************************************
   *                   Status Get/Set Functions
   * ************************************************************** */
  /** Return this task controller's task data structure.
   *   Use it responsibly!
   * NOTE : Use dynamic casts whenever you downcast the data.
   *        And try not to downcast very often. Perf hit. */
  virtual STaskBase* getTaskData()=0;

  /** Sets the current goal position. Returns false if not supported by task. */
  virtual bool setGoalPos(const Eigen::VectorXd & arg_goal) { return false; }

  /** Sets the current goal velocity. Returns false if not supported by task. */
  virtual bool setGoalVel(const Eigen::VectorXd & arg_goal) { return false; }

  /** Sets the current goal acceleration. Returns false if not supported by task. */
  virtual bool setGoalAcc(const Eigen::VectorXd & arg_goal) { return false; }

  /** Gets the current goal position. Returns false if not supported by task. */
  virtual bool getGoalPos(Eigen::VectorXd & arg_goal) const { return false; }

  /** Gets the current goal velocity. Returns false if not supported by task. */
  virtual bool getGoalVel(Eigen::VectorXd & arg_goal) const { return false; }

  /** Gets the current goal acceleration. Returns false if not supported by task. */
  virtual bool getGoalAcc(Eigen::VectorXd & arg_goal) const { return false; }

  /** Gets the current position. Returns false if not supported by task. */
  virtual bool getPos(Eigen::VectorXd & arg_pos) const { return false; }

  /** Gets the current velocity. Returns false if not supported by task. */
  virtual bool getVel(Eigen::VectorXd & arg_vel) const { return false; }

  /** Gets the current acceleration. Returns false if not supported by task. */
  virtual bool getAcc(Eigen::VectorXd & arg_acc) const { return false; }