Various and very importants (see comments below for details)

1) Renamed class QSR_Lib to QSRlib
2) Renamed request methods in QSRlib and in the QSRlib_ROS_Server
to have the same name "request_qsrs"
3) Renamed qsr_lib_ros_* to qsrlib_ros_*
4) Provided an example of using the QSRlib_ROS_Client for ease of
read
5) README updated to reflect the changes