[Development] 4.8 does not compile on OS X 10.11 - https://bugreports.qt.io/browse/QTBUG-48079

[Tim Blechmann]

> https://bugreports.qt.io/browse/QTBUG-48079
> 
> Looks like Apple began removing deprecated functions.
> 
> Since 4.8 is now closed for changes that aren't security-related, that means 
> 4.8 will not compile on OS X 10.11.

apple continuously evolves their API (read: break old code), but afaict
they don't remove the functions from their library. so one could simply
forward-declare these deprecated functions in qt...