Add support for mappingOptions in knockout.projections

Added support for new features introduced in knockout-projections,
mappingOptions parameters with either a mapping/disposeItem pair or a
single mappingWithDisposeCallback function which produces a
mappedItem/dispose pair.

knockout.projections/knockout.projections-tests.ts

@@ -26,3 +26,31 @@ sourceItems.push(9);
 
 sourceItems.push(10);
 // evenSquares now contains [36, 16, 4, 100]
+
+// Testing mapping options
+
+interface IComplexItem {
+    value: string;
+    dispose(): void;
+}
+
+var complexItems = sourceItems.map({
+    mapping: x => {
+        var item: IComplexItem = {
+            value: (x * x).toString(),
+            dispose: () => { }
+        };
+
+        return item;
+    },
+    disposeItem: (item: IComplexItem) => item.dispose()
+});
+
+var complexItems2 = sourceItems.map({
+    mappingWithDisposeCallback: x => {
+        return {
+            mappedValue: (x * x).toString(),
+            dispose: () => { }
+        };
+    }
+});

knockout.projections/knockout.projections.d.ts

@@ -6,7 +6,17 @@
 /// <reference path="../knockout/knockout.d.ts" />
 
 interface KnockoutObservableArrayFunctions<T> {
-
-    map<TResult>(mapping: (value: T) => TResult): KnockoutObservableArray<TResult>;
+    map<TResult>(mappingOptions: {
+        mappingWithDisposeCallback: (value: T) => {
+            mappedValue: TResult;
+            dispose: () => void;
+        };
+    }): KnockoutObservableArray<TResult>;
+    map<TResult>(mappingOptions: {
+        mapping: (value: T) => TResult;
+        disposeItem?: (mappedItem: TResult) => void;
+    }): KnockoutObservableArray<TResult>;
+    map<TResult>(mappingOptions: (value: T) => TResult): KnockoutObservableArray<TResult>;
+    
     filter(predicate: (value: T) => boolean): KnockoutObservableArray<T>;
 }