Add a method to detach the item from an item control without deleting it and
use it in wxRearrangeList to correctly swap object client data without
deleting the pointers in the process.
Closes#12201.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65040 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Use "wxWindows licence" and not "wxWidgets licence" (the latter doesn't
exist) and consistently spell "licence" using British spelling.
See #12165.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64940 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
