ENH: foamHelp - minro refactoring to enable use of foamHelp -help option

applications/utilities/miscellaneous/foamHelp/addToolOption.H

+argList::validArgs.append("tool");
+const wordList opts(helpType::dictionaryConstructorTablePtr_->sortedToc());
+
+string note = "Valid <tool> options include:";
+forAll(opts, i)
+{
+    note = note + ' ' + opts[i];
+}
+
+argList::notes.append(note);

applications/utilities/miscellaneous/foamHelp/foamHelp.C

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2012-2014 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -42,6 +42,14 @@ using namespace Foam;
 int main(int argc, char *argv[])
 {
     #include "addRegionOption.H"
+    #include "addToolOption.H"
+
+    // Intercept request for help
+    if ((argc > 0) && (strcmp(argv[1], "-help") == 0))
+    {
+        #include "setRootCase.H"
+    }
+
     if (argc < 2)
     {
         FatalError
@@ -49,8 +57,7 @@ int main(int argc, char *argv[])
             << exit(FatalError);
     }
 
-    const word utilityName = argv[1];
-
+    word utilityName = argv[1];
     Foam::autoPtr<Foam::helpType> utility
     (
         helpType::New(utilityName)

applications/utilities/miscellaneous/foamHelp/helpTypes/helpBoundary/helpBoundary.C

@@ -62,8 +62,6 @@ void Foam::helpTypes::helpBoundary::init()
 {
     helpType::init();
 
-    argList::validArgs.append("boundary");
-
     argList::addOption
     (
         "field",

applications/utilities/miscellaneous/foamHelp/helpTypes/helpFunctionObject/helpFunctionObject.C

@@ -61,8 +61,6 @@ Foam::helpTypes::helpFunctionObject::~helpFunctionObject()
 void Foam::helpTypes::helpFunctionObject::init()
 {
     helpType::init();
-
-    argList::validArgs.append("functionObject");
 }
 
 

applications/utilities/miscellaneous/foamHelp/helpTypes/helpSolver/helpSolver.C

@@ -63,7 +63,6 @@ void Foam::helpTypes::helpSolver::init()
 {
     helpType::init();
 
-    argList::validArgs.append("solver");
     argList::addBoolOption
     (
         "read",