Yandex.Maps

I've implemented [Yandex.Maps API](http://api.yandex.com/maps/) support in gmaps4rails.
You can find the current state of API implementation [here](https://docs.google.com/spreadsheet/ccc?key=0Aj752Hzwtd7GdDBsSjg3X1ZNWjJ5MHU1MzIxa0VzVnc&usp=sharing).