Improve run_command script handling

* Check for the existence of the script provided
* Pass an absolute path to the service

Reflect new messages with dynamic_graph_bridge_msgs catkinization.

The trigger signal cannot be destroyed.

Correct issue in ubuntu 13.04

This enables to directly launch a python file within any roslaunch file
Adapted by F.Keith for the extraction of the messages.

Some of the library were not generated in the lib folder,
 so linking with the dynamic_graph crashed.
Update the dependencies in packages: the dependency in jrl-dyn-urdf
 does not concern the ros package version anymore.

Fixes #22

Conflicts:

	include/dynamic_graph_bridge/ros_interpreter.hh
	src/ros_interpreter.cpp

Deregister the signal formerly added.
Add a mutex system to prevent removing a signal while triggering it,
 to avoid a crash (especially if the topic was listened to).

Update CMakeLists.txt to install libros_bridge

this will allow to close Issue #18

  It seems that everybody is still using the old style ROS build system...

  Previous commit was not on official repository.

  Fix distcheck target.

  Without this call the command fails.