ENH: isolate version information in foamVersion names instead of globals

- For compatibility, access to the old global names is provided via
  macros
        #define FOAMversion     foamVersion::version
        #define FOAMbuild       foamVersion::build
        #define FOAMbuildArch   foamVersion::buildArch

- this isolation makes it easier to provide additional scoped methods
  for dealing with version related information.  Eg, printBuildInfo()

applications/test/foamVersion/Make/files

@@ -1,3 +1,3 @@
-Test-foamVersionString.C
+Test-foamVersion.C
 
-EXE = $(FOAM_USER_APPBIN)/Test-foamVersionString
+EXE = $(FOAM_USER_APPBIN)/Test-foamVersion

applications/test/foamVersion/Make/options

@@ -1,2 +1,2 @@
-/* EXE_INC = -I$(LIB_SRC)/cfdTools/include */
-/* EXE_LIBS = -lfiniteVolume */
+/* EXE_INC = */
+/* EXE_LIBS = */

applications/test/foamVersion/Test-foamVersion.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2018 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -22,24 +22,39 @@ License
     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
 Application
-    foamVersionString.C
+    Test-foamVersion
 
 Description
-    Print the OpenFOAM version strings.
-
-    Simultaneously the smallest possible program to use a minimal bit of
-    the OpenFOAM library
+    Print the OpenFOAM version information.
 
 \*---------------------------------------------------------------------------*/
 
 #include <iostream>
 #include "foamVersion.H"
 
+using namespace Foam;
+
 int main()
 {
     std::cout
-        << "version " << Foam::FOAMversion << "\n"
-        << "build   " << Foam::FOAMbuild << "\n";
+        << "\nVersion information (macros)\n"
+        << "version   " << Foam::FOAMversion << '\n'
+        << "build     " << Foam::FOAMbuild << '\n'
+        << "buildArch " << Foam::FOAMbuildArch << '\n';
+
+    std::cout
+        << "\nVersion information (namespace)\n"
+        << "version   " << foamVersion::version << '\n'
+        << "build     " << foamVersion::build << '\n'
+        << "buildArch " << foamVersion::buildArch << '\n';
+
+    std::cout
+        << "\nVerify memory addesses are identical:\n"
+        << "macro     " << long(&(Foam::FOAMversion)) << '\n'
+        << "namespace " << long(&(foamVersion::version)) << '\n';
+
+    std::cout
+        << "\nEnd\n";
 
     return 0;
 }