Callback on highlighter deserialize

[axul]

I'm using rangy highlighter on a view with a lot of content, and I also have a view with a list of selections made by the user. With my app, I can tap or click on a selection within the list, and It will take me to the text view and scroll down to the selection I choosed. The thing is I can't scroll down to my selection if rangy is still deserializing after the view loads. It will be nice implementing a callback to highlighter.deserialize() (and other heavy funcs) so when the all the highlights are in the text, the page can scroll down to the chosen highlight.

[axul]

pull request with the callback #380