Revert "fTools::getSmallValue() is not used anymore"

to fix the build

This reverts commit ce7d80c6.

include/basegfx/numeric/ftools.hxx

@@ -151,10 +151,13 @@ namespace basegfx
     class BASEGFX_DLLPUBLIC fTools
     {
     public:
+        /// Get threshold value for equalZero and friends
+        static double getSmallValue() { return 0.000000001f; }
+
         /// Compare against small value
         static bool equalZero(const double& rfVal)
         {
-            return (fabs(rfVal) <= 0.000000001f);
+            return (fabs(rfVal) <= getSmallValue());
         }
 
         /// Compare against given small value