Project autoplot-run-tests

trigger all the autoplot tests, so that running all tests is decoupled from compiling.  This also checks that the X-Windows display is available.

Here is an example of how to find a test:
/var/local/jenkins/jobs
spot8> grep description autoplot-test*/config.xml  | grep cadence
autoplot-test014/config.xml:  <description>cadence tests</description>