Properly zoom the next window
Properly zoom the next window

* This calculates and maintains proper zoom levels on the next window.
  This means that the window is now resizable.
* Turns out that it working was simply an accident in the first
  place--all windows at that size used the mobile view already, which
  was already zoomed.
* This uses a zoom() function similar to the one in the presenter
  preview, but it's a slightly different algorithm.

berkes/showoff,wanix/showoff,marrero984/showoff,kublaj/showoff,kublaj/showoff,kublaj/showoff,berkes/showoff,marrero984/showoff,binford2k/showoff,marrero984/showoff,wanix/showoff,berkes/showoff,slambert/showoff,binford2k/showoff,berkes/showoff,binford2k/showoff,puppetlabs/showoff,wanix/showoff,kublaj/showoff,slambert/showoff,puppetlabs/showoff,slambert/showoff,puppetlabs/showoff,binford2k/showoff,berkes/showoff,puppetlabs/showoff,marrero984/showoff,kublaj/showoff,slambert/showoff