Creates a new Splitter object; can also be called as
PARENT->AddHeader(%OPTIONS). Class specific %OPTIONS
are:
-buttons => 0/1 (default 0) header items look like push buttons and can be clicked. -hottrack => 0/1 (default 0) -imagelist => Win32::GUI::ImageList object
Sent when the Splitter is released after being dragged to a new location (identified by the COORD parameter).