egl: assorted fixes for Windows

Note that int32_t is typedef'd both in p_compiler.h and eglplatform.h
diff --git a/SConstruct b/SConstruct
index 549ff64..8c8a82b 100644
--- a/SConstruct
+++ b/SConstruct
@@ -52,6 +52,7 @@
                      ['xlib', 'intel', 'gdi'])) 
 
 env = Environment(
+	MSVS_VERSION = '7.1',
 	options = opts, 
 	ENV = os.environ)
 Help(opts.GenerateHelpText(env))