Added custom title bar drawing block, titlebar alpha values, tidied code and updated preview .gif.

I've added a drawing block for the window's title bar, and made the window now default to the regular OS X title bar style, so that it really is a drop-in replacement for a NSWindow, and so that FOTWindow's use extends beyond just looking like QuickTime X to something that is customisable. The alpha values which the title bar will fade in and out to can also now be set.

Minor things: the code has been tweaked and tidied, with comments added, and the file structure has been updated (with a new preview gif).

Apologies for the large number of commits (> <).