Add map segment status bars, player count

[cheshire137]

This branch brings us closer to @smbriones' mockup by adding a count of how many players have been selected to the left column, and adding status bars for each map segment to indicate if the segment has been fully filled out with heroes.

The select menus look a little awkward right now with the text almost touching the little arrow on the right, but that should be fixed when #88 lands since it shortens the 'choose a X' text.

This also helps a little with #86 by widening the .container class.