more disconnecting the DOM from 2048

new F7U12 doesn't take a target anymore. It didn't need it. This
will make it a little easier to implement an AI using the available
methods. render() now takes the old target tag and now expects
an empty div it will populate from scratch.
use a less specific selection for dpad arrows
remove stray space
remove unneeded elements

F7U12 only needs a single div that it will fill in
add F7U12 plugin to draw a dpad

Point at the same target as the game and it will
append a table with the dpad in it. Events are not
wired up. See app.js.
move to new F7U12 API
enable the new F7U12 dpad plugin
only render one player for now