add config path to error message when available (fix #288)
add config path to error message when available (fix #288)

beni55/catkin,ros/catkin,beni55/catkin,harmishhk/catkin,wkentaro/catkin,shyamalschandra/catkin,shyamalschandra/catkin,asmodehn/catkin,wkentaro/catkin,meyerj/catkin,jack-oquin/catkin,jack-oquin/catkin,asmodehn/catkin,wkentaro/catkin,harmishhk/catkin,scpeters/catkin,jack-oquin/catkin,ros/catkin,harmishhk/catkin,thaddeustaylor/catkin,beni55/catkin,shyamalschandra/catkin,thaddeustaylor/catkin,thaddeustaylor/catkin,ros/catkin,asmodehn/catkin,meyerj/catkin,scpeters/catkin,scpeters/catkin,meyerj/catkin