Catkin

Hi Max, 
Looking at your comments with the last pull request, I deleted the hack with the messages and I have extracted those messages from the ar_pose package to a single ar_tools_msgs.

From my point of view this is the right way to have the messages, however this can imply considerable changes to the packages that are currently using them (changes with the #includes). Also, we have to consider that this tools are without active maintenance from the authors.

What do you think about it?

Thanks for your replies. 

Àngel.