Adding gaussian noise part

Closes #357 (closed)

src/include/qnorm.h

@@ -126,7 +126,7 @@
 
 // This is a simplified 9th order Taylor polynomial for e^x
 //
-// This has a maximum abs error of 0.00000033 over the (0,1)
+// This has a maximum percent error of 0.000011% over the (0,1)
 // range, which is where we use it here
 //
 static inline double taylor_9th_exp(double x)
@@ -154,8 +154,8 @@ fastlog2 (float x)
            - 1.72587999f / (0.3520887068f + mx.f);
 }
 
-// The maximum error over the (0,1] range is 0.000101
-// with the use of this acceleration 
+// The maximum error over the (0,1] range is a percent error of
+// 0.000773% with the use of this acceleration 
 static inline float
 fastlog (float x)
 {