Limit interfaces do not play well with ros_canopen

[mathias-luedtke]

The current implementation of https://github.com/ros-controls/ros_control/tree/indigo-devel/joint_limits_interface does not work properly for all use cases, see https://github.com/ros-controls/ros_control/issues/193 as well.

[mathias-luedtke]

• plugin-based limiter (output filter) system
• implementation of open-loop limiter
• end position limiter: full stop
• per controller configuration

[mathias-luedtke]

• remove joint_limit_interface code in favour of https://github.com/ipa320/cob_control/issues/72
• restrict 402 commands to bounds according to mode
• URDF will not be needed anymore (addresses #145)

[mathias-luedtke]

• warn about missing limiter (indigo only)

[mathias-luedtke]

Preliminary implementation is done in https://github.com/ros-industrial/ros_canopen/tree/limited_joint_handle

[fmessmer]

A summary about current approaches and insights regarding "limit interfaces" is given in https://github.com/ipa320/cob_gazebo_plugins/issues/14#issuecomment-274255606

[mathias-luedtke]

For now joint_limits_interface can be turned off for specific controllers (#215 and #216).