Pass movesubpages to API in move()

I kept on wondering, why does only one page get moved with `{ movesubpages => 1 }`?  Looks like the option never gets passed to the API, so it was a nice one-line fix that works for me.  You have `watch`, `unwatch`, and `ignorewarnings` in the documentation, but they also don't get added to the API call -- those might need to be added too.