Added stats & download as popup menus

The stats & download views are loaded dynamically, so they'll be
reloaded each time you hit them. Click the button to open, click again
to close.

It gracefully degrades in the wonky condition in which js is turned off,
even if the rest of showoff is über reliant on js.

You can right click on the button and open in new window to actually get
a new window/tab. You can right click on the files listed to get a link
to the file instead of downloading it. Etc.
Merge pull request #45 from binford2k/popup_dialogs

Added stats & download as popup menus
Added an iPhone presenter mode

Only worked up the portrait mode. Landscape mode is passable.

This allows the presenter to view notes, to tap and swipe, use the menu
to choose a slide, etc. from the phone.
Cleaned up presenter follow mode a bit

Now the remote properly switches slides on the presenter deck.
Style improvements

The slide now fills the available area
The slide source won't push the update button off
Fits on both iPhone 5 and iPhone 4 screens.
Allow remote tracking to be disabled

Adds a toggle to presenter mode that allows the presenter to disable
tracking of remote presenters.
Cleaned up styling a bit more.
Added an iPhone viewing mode, non presenter
Comment out landscape until it works
Merge pull request #46 from binford2k/iphone_presenter_mode

Added an iPhone presenter mode