Fullscreen

Enabled Lion style fullscreen support. Unfortunately, this makes all
but the primary screen worthless, unlike the original fullscreen.
Maybe support for real fullscreen can be added later.
Current Frame Index name change

The current frame index in the model is now known ass currentFrameIdx
instead of currentFrame.
CBRangeBuffer subrange enumeration

New methods allow the iteration over subranges of the full range. The
full range iteration is now implemented in terms of this subrange iteration.
Asynchronous Frame and Page Loading

Frames are now loaded in a separate thread and sent asynchronously to
the model in the main thread. By observing the frameCount the view
is informed and updates its pages with newly available images. If the
desired current page becomes available, the view jumps to it.
Decoding frames asynchronously showed that parts of XADM are not thread
safe, so access to each archive is synchronized.