Document qtmacextras functions

This patch aims to provide the missing Qt Mac Extras documentation

The conversion functions (e.g. NSData <=> QByteArray) are not
documented because they will either be moved to QtCore or
removed from QtMacExtras since already present in QtCore

Change-Id: I364be524966b353602bcf88218d9bb81042497ff
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Removed duplicate NSString NSURL conversion functions

Currently there's a duplication of the QString <-> NSString and
QUrl <-> NSURL functions.
This patch removes the private implementation and updates the code to
to use QtCore's functions directly.

Change-Id: I8fa613ac6753cc16fedd208f676f39ee2fec6bfa
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Prefer to use normalised signal/slot signatures

Change-Id: Ifeb9739ae25c09e3c8ff4100380d3d445b9548e1
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Document obsolete from/toNSData functions

This patch adds the obsolete documentation for fromNSData and toNSData
to conform to the documentation process. See comments in the bug
report

Task-number: QTBUG-36985
Change-Id: I7a9b69fa99c8b53c002a95bd9c70cc64006cd59e
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: I11df18cceb1decbd0bf723f9911a5f985eb7d59f