Pagination

Hi,

first of all thank you for creating this great tool. We have been using it right from the start in our project and it worked perfectly. However as soon as we added a lot of items in the Om app state, ankha started to become more and more unresponsive until the point where it crashed the browser.

The pull request contains two changes. The first change cfe77bcc64637d70a41021b6a96503fd0b5bb59a takes care that the data of the parent element is not over and over repeated in the data-reactid attributes of its child elements. With this change the browser crash could be avoided with the size of our Om app state.

But the browser is still very unresponsive until the rendering is done. Therefore the second change c14b7b346c3a91ec4773fb9cc2070825ba70bc55 adds a pagination feature to ankha that enables it to stay responsive even if the Om app states contains hundreds or thousands of items.

I hope my formatting and the coding style is okay. If you like to have any changes I'm happy to include them. I would be glad, if this feature would make it into the ankha master (maybe as optional feature).

Best regards

Max