- for tutorials that are known to run poorly, can provide a
  placeholder Allrun-optional instead of the usual Allrun script.
  If this is detected, the case will be skipped.

RunFunctions: Added "isTest()" argument parsing function
tutorials: Updated Allrun scripts to propagate the "-test" option
tutorials: Removed the lower Alltest scripts and updated the Allrun to
    use the "isTest()" function to handle test-specific operation

foamRunTutorials now accepts two arguments:
-test : Preferentially execute Alltest, if present, over Allrun.
-skipFirst : Skip Alltest/Allrun at the top level to prevent recursion

Added because some tutorials are not dependent on controlDict and take
a long time.

This reverts commit c5bea524.

This reverts commit 2e1e671d.