COMP: some low-level darwin-related patches

- a partial selection from https://github.com/mrklein/openfoam-os-x
  with adjustments. The primary purpose is to reduce header-level
  incompatibilities and to provide a common set of make rules to allow
  easier patching (or re-integration).

src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.H

@@ -44,7 +44,7 @@ SourceFiles
 namespace Foam
 {
 
-// Forward declaration of classes
+// Forward declarations
 class dynamicCodeContext;
 class ISstream;
 class OSstream;
@@ -92,11 +92,11 @@ private:
 
     // Private Member Functions
 
-        //- Disallow default bitwise copy construct
-        dynamicCode(const dynamicCode&);
+        //- No copy construct
+        dynamicCode(const dynamicCode&) = delete;
 
-        //- Disallow default bitwise assignment
-        void operator=(const dynamicCode&);
+        //- No copy assignment
+        void operator=(const dynamicCode&) = delete;
 
 
 protected:
@@ -221,7 +221,11 @@ public:
         //  Corresponds to codeRoot()/libSubDir()/lib\<codeName\>.so
         fileName libPath() const
         {
+            #ifdef darwin
+            return codeRoot_/libSubDir_/"lib" + codeName_ + ".dylib";
+            #else
             return codeRoot_/libSubDir_/"lib" + codeName_ + ".so";
+            #endif
         }
 
         //- Path for specified code name relative to \$FOAM_CASE