added filter, map, to SugarRecordResults

library/Core/SugarRecordResults.swift

@@ -116,3 +116,22 @@ public class SRResultsGenerator: GeneratorType {
         return self.results[nextIndex--]
     }
 }
+
+//MARK: Convenience Methods Extension
+
+extension SugarRecordResults {
+    func filter<T>(predicate:(T) -> Bool) -> [T] {
+        var result = [T]()
+        for obj in self {
+            if predicate(obj as T) { result.append(obj as T) }
+        }
+        return result
+    }
+    func map<T, U>(transform:(T) -> (U)) -> [U] {
+        var result = [U]()
+        for obj in self {
+            result.append(transform(obj as T))
+        }
+        return result
+    }
+}