add node v0.12 and io.js compatibility

src/node_map.cpp

@@ -239,7 +239,7 @@ void NodeMap::renderFinished() {
     assert(!image);
 
     if (img) {
-        v8::Local<v8::Object> result = v8::Object::New();
+        auto result = NanNew<v8::Object>();
         result->Set(NanNew("width"), NanNew(img->width));
         result->Set(NanNew("height"), NanNew(img->height));
 
@@ -283,7 +283,11 @@ NodeMap::NodeMap(v8::Handle<v8::Object> source_) :
     NanAssignPersistent(source, source_);
 
     async->data = this;
+#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
     uv_async_init(uv_default_loop(), async, [](uv_async_t *as, int) {
+#else
+    uv_async_init(uv_default_loop(), async, [](uv_async_t *as) {
+#endif
         reinterpret_cast<NodeMap *>(as->data)->renderFinished();
     });
 
@@ -292,7 +296,7 @@ NodeMap::NodeMap(v8::Handle<v8::Object> source_) :
 }
 
 NodeMap::~NodeMap() {
-    source.Dispose();
+    NanDisposePersistent(source);
 
     uv_close(reinterpret_cast<uv_handle_t *>(async), [] (uv_handle_t *handle) {
         delete reinterpret_cast<uv_async_t *>(handle);