maps: poll for mapbox

poll strategy. could be generalized as part of the revamped spice api.

@yegg 
@nilnilnil 

console logs left in so we can see it. for me, tonight, I get 6-8   50ms polls before it loads. Also apparently I'm in either witchita or northern virginia  on my FIOS subnet for this. ip 108.2.173.36, but duckduckgo tells me that's in Blue Bell PA ...