FIX: add version macro prefix

Author: mikewei

src/gtestx/gtestx.h

@@ -45,10 +45,10 @@
  */
 
 // conform to Semantic Versioning (http://semver.org)
-#define MAJOR_VERSION 1
-#define MINOR_VERSION 0
-#define PATCH_VERSION 0
-#define PRERLEASE_VERSION beta
+#define GTESTX_MAJOR_VERSION 1
+#define GTESTX_MINOR_VERSION 0
+#define GTESTX_PATCH_VERSION 0
+#define GTESTX_PRERLEASE_VERSION beta
 
 #define PERF_ABORT (Perf::Abort(), "Perf loop aborted!")