Remove accidentally committed debugging fragment

Also remove a stray curly brace
Flatten loader closure, adjust event callback

The inner loader closure was redundant. Apparently I really like closures
during late night coding.

main.js should no longer have to deal with raw loading events; only UI
specific callbacks.
Style changes

Based off bootstrap
Make map chart and user list bigger
Update d3 submodule, use Freeyorp/d3.git for now

Upstream merge on exposing xhr.responseType pending.
Implement remote resource loading

mv.loader.use takes an array of URLs, which are fetched via d3.xhr.

This also restructures mv.loader to refactor out some shared functionality
between mv.loader.use and the file selector change events.
mv.loader could still use some cleanup.

http://css-tricks.com/examples/ButtonMaker/ makes a pretty neat css button.
Hopefully, it's visually attractive enough so people in a hurry know where
to go. :)
Set sensible min-height