renamed rollerMatch offset() to size()

roller.hpp

                 return (match == (roller.value() & mask));
             }
 
-            size_t offset() { return matchLength; }
+            size_t size() { return matchLength; }
     };
 
     class RollerMatch64 {
                 return (match == (roller.value() & mask));
             }
 
-            size_t offset() { return matchLength; }
+            size_t size() { return matchLength; }
     };
 }