[NEW]: make the screenshot manager self-contained
In order not to bother with macros and #ifs, we just create an instance inside the screenshot manager, which should only be compiled when it's needed anyway.
[NEW]: get rid of UIGetScreenImage, since it's no longer supported
It seems UIGetScreenImage is no longer supported, and it doesn't compile for me, so I switched to the drawViewHierarchyInRect: approach. Admittedly, this doesn't render the status bar, but can easily be fixed by adding a fake one, which we don't need, so it wasn't implemented.
Merge branch 'new-screenshot-code'

* new-screenshot-code:
  [NEW]: get rid of UIGetScreenImage, since it's no longer supported It seems UIGetScreenImage is no longer supported, and it doesn't compile for me, so I switched to the drawViewHierarchyInRect: approach. Admittedly, this doesn't render the status bar, but can easily be fixed by adding a fake one, which we don't need, so it wasn't implemented.