Avoid selecting invalid tab when removing last page from wxOSX wxNotebook.

Closes #15897 (backport of r75663 from trunk).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76319 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Call wxDataViewRenderer::Validate() under OS X too.

Ensure that the custom renderers get a chance to validate (and maybe change)
the value entered by user, as previously it was completely impossible with the
native OS X implementation of wxDataViewCtrl.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76320 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix crash when playing invalid sounds under wxOSX.

Sound ID 0 is not actually invalid, it is returned by
AudioServicesCreateSystemSoundID() when it fails to open the file and
currently we don't consider this to be an error. However, because we never
called AudioServicesDisposeSystemSoundID() for this sound ID, we continued to
receive the notifications from the callback registered by
AudioServicesAddSystemSoundCompletion() for it even after the corresponding
sound object was destroyed, resulting in crashes when playing it more than
once.

Fix this by keeping a separate flag indicating whether we're playing a sound
and always disposing of the sound if we are, even if ID is 0.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76321 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775