Feature arglist option aliases

Allows migration of command-line options, with versioning to track the 'age' of the changes. Eg, if -decomposeParDict gets changed to something like -decompose-dict, but we still wish to accept the older name for it:

argList::addOptionCompat("decompose-dict", { "decomposeParDict", 1612});
argList::addOptionCompat("no-function-objects", {"noFunctionObjects", 1612});

This emits a warning about the option being out of date, but will rewrite it with the newer option name, which is what would be referenced internally.

applications/test/argList/Test-argList.C

@@ -38,12 +38,24 @@ int main(int argc, char *argv[])
 {
     argList::noBanner();
     argList::noParallel();
-    argList::noFunctionObjects();
+    // argList::noFunctionObjects();
     argList::removeOption("case");
 
     argList::addOption("label", "value", "Test parsing of label");
     argList::addOption("scalar", "value", "Test parsing of scalar");
 
+    // These are actually lies (never had -parseLabel, -parseScalar etc),
+    // but good for testing...
+
+    // Emits warning about it being old
+    argList::addOptionCompat("label", {"parseLabel", 1612});
+
+    // Specifying version=0 to use alias without any warnings
+    argList::addOptionCompat("scalar", {"parseScalar", 0});
+
+    // Fake a future option...
+    argList::addOptionCompat("label", {"parse-label", 2112});
+
     argList args(argc, argv);
 
     label ival;