Add tests that make it easier to take the pulse of vtk on cdash

One script just summarizes what is going on, so that you
can see what tests fail the most and focus on them.

The other scrapes the dashboard results for relevant results from
testsysteminformation so that you can determine what we cover and
what we don't.

Change-Id: I142f829a5d362f66799b9bdacd2ac7d513d69b3f
Add better comments and handle case of no cdash result better.

Change-Id: I01398069d954512bf3147a3338563368e4abf121
Merge topic 'cdash_discover' into master

33694eee Add better comments and handle case of no cdash result better.
2bc6f2df Add tests that make it easier to take the pulse of vtk on cdash