Added Python/dtoa.c to project files.
diff --git a/PC/VS7.1/pythoncore.vcproj b/PC/VS7.1/pythoncore.vcproj
index e24e573..d60f792 100644
--- a/PC/VS7.1/pythoncore.vcproj
+++ b/PC/VS7.1/pythoncore.vcproj
@@ -517,6 +517,9 @@
 			RelativePath="..\..\PC\dl_nt.c">
 		</File>
 		<File
+			RelativePath="..\..\Python\dtoa.c">
+		</File>
+		<File
 			RelativePath="..\..\Python\dynload_win.c">
 		</File>
 		<File