Launch files reorganization and documentation

[marcoesposito1988]

Hi guys, I would like to propose some changes:

• Extensively updated documentation
• New package lwr_launch with README
• _lwr_launch/lwrlaunch.launch is basically the old _lwrdescription/display.launch (which was removed) without the MoveIt! parts (which belong to the lwr_moveit package launch files)
• Added controller, IP and port arguments to _lwr_launch/lwrlaunch.launch
• lwr_controller launch files reorganized:
  • _loadcontroller.launch takes a "controller" argument (e.g. roslaunch lwr_controller load_controller.launch controller:=JointImpedanceControl)
  • other controller launch files just include _loadcontroller.launch and set this parameter in order to load the different controllers; this is just syntactic sugar, in order to avoid typing the controller's name every time and just usei instead tab completion from the shell

This means that the simulator and the OneTaskInverseKinematics controller can be launched with the default arguments: roslaunch lwr_launch lwr_launch.launch The controller can be changed with the "controller" argument: roslaunch lwr_launch lwr_launch.launch controller:=ComputedTorqueControl The connection to the real robot can be esablished with the "_use_lwrsim" argument: roslaunch lwr_launch lwr_launch.launch controller:=ComputedTorqueControl use_lwr_sim:=false

• New launch file _lwr_moveit/moveit_planningexecution.launch that allows to start everything needed to move the robot with MoveIt! (the real one, or an automatically spawned simulated one, depending on the value of the sim argument). It loads the joint_trajectory_controller.

I look forward to your feedback.

[carlosjoserg]

It seems ok to me, so I'll merge it. Thanks for the contribution.