Fix for issue #10 (exporting of library files)

Fix for issue #10.  The robot client and simple message libraries were both exporting their libraries using the catkin_package macro.  This resulted in multiple definitions of the same functions (one byte swapped, the other not).  Any package linking to simple message or the robot client could link to the incorrect method.  The libraries have been removed from the macro and any package with a dependency must explicitly link to the correct library by name.  (other pull related pull requests will occur as a result).