Change deprecated comments that still talk about SCons.

src/version.cc

Index: src/version.cc
diff --git a/src/version.cc b/src/version.cc
index b47a7e57613e473f913adb9ed6ab23b97745c9d2..720bbc900a372774fdf201d9645d6f3dfe48b70f 100644
--- a/src/version.cc
+++ b/src/version.cc
@@ -30,8 +30,8 @@
 #include "version.h"
 
 // These macros define the version number for the current version.
-// NOTE these macros are used by the SCons build script so their names
-// cannot be changed without changing the SCons build script.
+// NOTE these macros are used by some of the tool scripts and the build
+// system so their names cannot be changed without changing the scripts.
 #define MAJOR_VERSION     3
 #define MINOR_VERSION     18
 #define BUILD_NUMBER      3
@@ -40,9 +40,9 @@
 // (Boolean macro values are not supported by all preprocessors.)
 #define IS_CANDIDATE_VERSION 1
 
-// Define SONAME to have the SCons build the put a specific SONAME into the
+// Define SONAME to have the build system put a specific SONAME into the
 // shared library instead the generic SONAME generated from the V8 version
-// number. This define is mainly used by the SCons build script.
+// number. This define is mainly used by the build system script.
 #define SONAME            ""
 
 #if IS_CANDIDATE_VERSION