Comparing the traditional `catkin_make` to `catkin_make_isolated` and `catkin build`

These aren't incredibly scientific; they're just designed to give me an idea of how the various existing build tools compare with one another. They're tested on the fairly large project I work on at my day job.

Tool|catkin_make|catkin_make_isolated|catkin_tools
----|-----------|--------------------|------------
Build from scratch|8m2s|12m33s|8m47s
Rebuild, no changes|2s|19s|27s
Touch a cmakelists|52s|41s|59s
Touch a header|2m7s|2m38s|3m6s
Touch cmakelists in leaf package|43s|19s|28s
Touch a source file in leaf package|8s|24s|28s