Deprecate QByteArray <=> NSData converters for 5.3

The NSData conversion functions have been moved to QtCore so deprecate
their use in QtMacExtras.

Change-Id: I0e78b32c803a2856366d15302c96014af3ef4c34
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Doc: Improved example documentation.

-updated copyright year
-added instruction for running the example from within Qt Creator
 (using \include)
-added links to relevant pages
-qdocconf change needed for \include

Task-number: QTBUG-33597
Change-Id: I19ab712d0e74503d618c49633951d1628f822668
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>
Merge remote-tracking branch 'origin/release' into stable

Change-Id: I56a541591b5be2ab5672735d5fe4e26b98c3d77c