catch FirmwareException in refreshEncoders()

This can happen if the arm collides with something.
katana_arm_gazebo: increase goal tolerances for katana_arm_controller

This fixes the following sporadic error when executing MoveIt plans:

    Controller katana_arm_controller failed with error code GOAL_TOLERANCE_VIOLATED
katana_gazebo_plugins: reduce gripper duration to 3 seconds

This is the same value as in the real gripper controller.
katana JTAC: improve logging in goalReached()
Katana300: change joint positions for testSpeed()

original author: Steffen Pfiffner <pfiffnst@hs-weingarten.de>
katana: pass isPreemptRequested to executeTrajectory()

original author: Steffen Pfiffner <pfiffnst@hs-weingarten.de>
Katana300: override executeTrajectory() implementation

This implementation is based on kni->sendSplineToMotor(), which is
supported by the Katana 300 (in contrast to the
setAndStartPolyMovement() used with the Katana450).

closes #6

original author: Benjamin Reiner <reinerbe@hs-weingarten.de>
Katana300: don't check whether goal position was reached in allMotorsReady()

This usually returned false and looked strange anyway (compare to the
implementation in Katana.cpp instead).

original author: Steffen Pfiffner <pfiffnst@hs-weingarten.de>
Katana300: increase motor acc/vel limits

original author: Benjamin Reiner <reinerbe@hs-weingarten.de>
Katana300: Made arm slower + spinOnce in executeTrajectory
Katana300: Release lock for a short time, so that the robot state publisher can publish the joint state
Katana300: stop arm immediately when trajectory is canceled
katana_gazebo_plugins: replace deprecated function calls
katana_gazebo_plugins: remove unused constant
katana_gazebo_plugins: don't update controller gains in each timestep

The problem was that starting with Hydro, control_toolbox supports
dynamic_reconfigure. That means there is a certain overhead (log
entries, cpu) whenever setGains() is called. Previously, it was called
in each simulation cycle, which was unnecessary anyway. This commit
fixes that.

* avoids gigabytes of log output
* speeds up simulation by a factor of 3-4
* fixes #7
katana_arm_gazebo: remove outdated script + info

The gripper no longer supports the GraspHandPostureExecutionAction;
instead, it offers the GripperCommand action.
katana_teleop: update manifest (control_msgs)

This dependency is needed for the control_msgs/GripperCommand.
Strangely, it also compiled before...