Add the GenerateExportMacro with unit tests.

Reviewed-by: Marcus D. Hanwell <marcus.hanwell@kitware.com>

Tests/Module/GenerateExportHeader/libshared/libshared.cpp

@@ -0,0 +1,91 @@
+
+#include "libshared.h"
+
+int Libshared::libshared() const
+{
+  return 0;
+}
+
+int Libshared::libshared_exported() const
+{
+  return 0;
+}
+
+int Libshared::libshared_deprecated() const
+{
+  return 0;
+}
+
+int Libshared::libshared_not_exported() const {
+  return 0;
+}
+
+int Libshared::libshared_excluded() const {
+  return 0;
+}
+
+int LibsharedNotExported::libshared() const
+{
+  return 0;
+}
+
+int LibsharedNotExported::libshared_exported() const
+{
+  return 0;
+}
+
+int LibsharedNotExported::libshared_deprecated() const
+{
+  return 0;
+}
+
+int LibsharedNotExported::libshared_not_exported() const {
+  return 0;
+}
+
+int LibsharedNotExported::libshared_excluded() const {
+  return 0;
+}
+
+int LibsharedExcluded::libshared() const
+{
+  return 0;
+}
+
+int LibsharedExcluded::libshared_exported() const
+{
+  return 0;
+}
+
+int LibsharedExcluded::libshared_deprecated() const
+{
+  return 0;
+}
+
+int LibsharedExcluded::libshared_not_exported() const {
+  return 0;
+}
+
+int LibsharedExcluded::libshared_excluded() const {
+  return 0;
+}
+
+int libshared() {
+  return 0;
+}
+
+int libshared_exported() {
+  return 0;
+}
+
+int libshared_deprecated() {
+  return 0;
+}
+
+int libshared_not_exported() {
+  return 0;
+}
+
+int libshared_excluded() {
+  return 0;
+}