Added expert option for WrapAppiconsInDock property to WPrefs
In 2013 Daniel added the functionality to wrap icons, which are
attached to the dock, around the screen edges when the dock is
being moved vertically.
This patch adds an expert option to WPrefs.app for setting the
property which enables/disables this feature.
Remark: In my opinion, the default value for that property should
be changed to NO, as this is also the default behavior in
NeXTSTEP. It is handy to be able to move all these icons
out of sight when working with maximized application
windows.