Rewrite the Mac native toolbar classes.

Rename the classes to QMacToolBar and QMacToolBarItem.
(Keep the Qt-style ToolBar name capitalization.)

API-review and document a core set of the API, remove
the rest. Missing functionality can be added back
later on.

Add a simple QWindow-based mactoolbar example that
shows the core toolbar functionality. Add manual
test for more comprehensive testing.

Make the QToolbarItem properties actually work,
you can now change the text and icon after the
toolbar has been displayed.

Update license headers.

Change-Id: I99fb207df7f1b3cf0d5df178aa863c77cd372a1f
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Use setNSToolbar from the cocoa platform plugin

The platform plugin will attach the toolbar to the
NSWindow when the NSWindow is created.

Change-Id: I550516a240df1f8ae94da2a225d9f63c76fffc6b
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Bump module version to 5.4.0

Change-Id: I475b7592ab787956cc37f11eb880e406ac3fe05a
Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>