update exercise 1.4 to catkin
update excercise 1.5 to catkin
fix maintainer
add catkin workspace files to exercise 1.4
update training unit script to generate setup.bash files from catkin workspaces
convert exercise 1.6 to catkin
update exercise 2.1 to catkin
convert exercise 2.2 to catkin
revert changes to exercise 2.1 source files
tweak training units script to not show catkin_make output and remove build directory if present