Fix use of cmTypeMacro in new command classes

Both commit 8a37ebec (Add the target_include_directories command,
2013-01-01) and commit fc61a7a7 (Add the target_compile_definitions
command, 2013-01-08) added command implementations deriving from the new
cmTargetPropCommandBase class.  Fix cmTypeMacro declarations of the
inheritance relationship.

Source/cmTargetPropCommandBase.h

@@ -31,6 +31,7 @@ public:
   bool HandleArguments(std::vector<std::string> const& args,
                            const char *prop, ArgumentFlags flags = NO_FLAGS);
 
+  cmTypeMacro(cmTargetPropCommandBase, cmCommand);
 protected:
   std::string Property;
   cmTarget *Target;