Add autoplay default delay parameter

[jeepin95]

The autoplay feature is nice, but it would be even better if we could either add a value to the parameter for the default delay, or have a configuration option for each story page to set the default delay so that some pages could delay longer than others.

It would also be nice to have an option to force a refresh of pages after X number of loops so that a storymap on autoplay can catch any updates to the story that were made in the background.