Issue 1106 - Add currentVersion Pref and compareVersions API

src/FilterEngine.cpp

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 316 matching lines @@
 {
   jsEngine->RemoveEventCallback("filterChange");
 }
 
 void FilterEngine::FilterChanged(FilterEngine::FilterChangeCallback callback, JsValueList& params)
 {
   std::string action(params.size() >= 1 && !params[0]->IsNull() ? params[0]->AsString() : "");
   JsValuePtr item(params.size() >= 2 ? params[1] : jsEngine->NewValue(false));
   callback(action, item);
 }
+
+int FilterEngine::CompareVersions(const std::string& v1, const std::string& v2)
+{
+  JsValueList params;
+  params.push_back(jsEngine->NewValue(v1));
+  params.push_back(jsEngine->NewValue(v2));
+  JsValuePtr func = jsEngine->Evaluate("API.compareVersions");
+  return func->Call(params)->AsInt();
+}