foamRunTutorials: Rationalized support for the "-test" option

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

tutorials/mesh/snappyHexMesh/Allrun

@@ -4,7 +4,7 @@ cd ${0%/*} || exit 1    # Run from this directory
 
 (
     cd flange || exit
-    ./Allrun
+    ./Allrun $*
 )
 
 exit 0