Add wxBitmap(NSImage*) ctor to wxOSX.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73574 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add support for Cocoa's selectable toolbar items.

The support is currently limited to making all toolbar items selectable
and is only available in wxOSX with Cocoa and native toolbars.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73575 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add wxPreferencesEditor class.

Implements native UI for preferences editing.  In particular, the API
handles the differences between modal (Windows) and non-modal (OS X) preferences windows and provides platform's native look.

Currently implemented natively for wxOSX/Cocoa, wxGTK and Windows (the latter is used as a fallback generic implementation as well).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73576 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add preferences sample.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73577 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775