Use NSDatePicker to implement both of these controls. Almost all of
wxDatePickerCtrl styles are not supported in the native version but the basic
functionality does work and looks much better than the generic version (which
is still available as wxDatePickerCtrlGeneric if needed) under Mac.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70071 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Implement wxTimePickerCtrl natively for MSW and add a generic implementation
(very loosely based on the original class by Paul Breen) for the other
platforms.
Also update the calendar sample to show the new control.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69224 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
