Rectify: remember last map view

[jidanni]

When we push "rectify" by default we start at a whole world view. Perhaps simply remember where the user was recently looking last time he used it on a previous map, and start there instead. Sort of like on OSM.org, if I was looking at Alabama last time I used the site, a year later in the same browser, that's where I'll be looking initially again, logged in or not.