XLSForm spec proposal: auto-location type for background location capture with setlocation action

In the TSC call, there was discussion of changing the action name to setgeopoint. Let's finalize that naming at Spec addition proposal: location preload - #14 by LN and then this spec can be made consistent with the action name.

Excellent point. Is that an argument for naming the type something more like auto-start-location, then? Or perhaps just start-location since the fact that it's linked to a particular event implies that it's automatic? That would be nicely analogous to the start and end time preloads.