No real change, just make bezel setting code in wxOSX more clear.

No real change, just make bezel setting code in wxOSX more clear.

Avoid code duplication between SetAcceleratorFromLabel() and
wxWidgetImpl::CreateButton(), generalize the former to handle the special
cases taken into account only in the latter previously.

Also use a switch on border flags instead of series of nested ifs as this
seems to be more clear.

No changes in behaviour.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72884 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775