Automatically add default filter subscription when necessary.

src/FilterEngine.cpp

Index: src/FilterEngine.cpp
===================================================================
--- a/src/FilterEngine.cpp
+++ b/src/FilterEngine.cpp
@@ -129,31 +129,38 @@ bool Subscription::IsUpdating()
 }
 
 bool Subscription::operator==(const Subscription& subscription) const
 {
   return GetProperty("url")->AsString() == subscription.GetProperty("url")->AsString();
 }
 
 FilterEngine::FilterEngine(JsEnginePtr jsEngine)
-    : jsEngine(jsEngine), initialized(false)
+    : jsEngine(jsEngine), initialized(false), firstRun(false)
 {
-  jsEngine->SetEventCallback("init", std::tr1::bind(&FilterEngine::InitDone, this));
+  jsEngine->SetEventCallback("init", std::tr1::bind(&FilterEngine::InitDone,
+      this, std::tr1::placeholders::_1));
   for (int i = 0; !jsSources[i].empty(); i += 2)
     jsEngine->Evaluate(jsSources[i + 1], jsSources[i]);
 
   // TODO: This should really be implemented via a conditional variable
   while (!initialized)
     ::Sleep(10);
 }
 
-void FilterEngine::InitDone()
+void FilterEngine::InitDone(JsValueList& params)
 {
   jsEngine->RemoveEventCallback("init");
   initialized = true;
+  firstRun = params.size() && params[0]->AsBool();
+}
+
+bool FilterEngine::IsFirstRun() const
+{
+  return firstRun;
 }
 
 FilterPtr FilterEngine::GetFilter(const std::string& text)
 {
   JsValuePtr func = jsEngine->Evaluate("API.getFilterFromText");
   JsValueList params;
   params.push_back(jsEngine->NewValue(text));
   return FilterPtr(new Filter(func->Call(params)));