multiValveEngineState: New functionObject to print and log the piston and valve motion

for the multiValveEngine fvMeshMover.  This replaced the hard-coded messages
printed by the multiValveEngine class, providing automatic logging of the piston
and valve speed and position and easy user extension or replacement to provide
additional case-specific diagnostics without having to hack the core
multiValveEngine code.  A functionObject configuration file is provided so that
the simple line

can be added to the system/functions file to enable this functionObject.

tutorials/fluid/engine2Valve2D/system/functions

@@ -14,6 +14,7 @@ FoamFile
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+#includeFunc multiValveEngineState
 #includeFunc checkMesh(executeControl=adjustableRunTime, executeInterval=5)
 
 // ************************************************************************* //