Added few line to enable instantuation of forceTorque plugin from
factory
Changes in CMakefile to install config files in the build folder
to make them availables for the ResourceFinder.

To have it works out in a user-friendly way the following
environmental variables has to be set:

YARP_ROBOT_NAME the name of the robot, in this case it is OffRoad
YARP_DATA_DIRS has to be expanded to include projectBuildFolder/share/robotran

In order to find the Exec executable it can be installed in some system path
or the PATH variable can be extended to include the build/bin folder