expose SETUPTOOLS_DEB_LAYOUT as option again (#418)
expose SETUPTOOLS_DEB_LAYOUT as option again (#418)

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