added boost header and btQuaternion header to fix errors related to boost and btQuaternion

I forked and clone this repository  and build.I got errors related to boost such as "undefined reference to boost::units"and btQuaternion related errors like "btQuaternion was not declared in this scope". So i just added the below mentioned two header lines in error related packages.

#include <tf2/LinearMath/btQuaternion.h>
#include <boost/units/io.hpp>


I am using ubuntu 12.10 with groovy.

Thanks
Regards 
Shehzad Ahmed