Forgot error_string.h/cc from previous commit

base/error_string.h

@@ -0,0 +1,16 @@
+#ifndef BASE_ERROR_STRING_H
+#define BASE_ERROR_STRING_H
+
+#include <string>
+
+//----------------------------------------------------------------
+
+namespace base {
+	// There are a couple of version of strerror_r kicking around, so
+	// we wrap it.
+	std::string error_string(int err);
+}
+
+//----------------------------------------------------------------
+
+#endif