Add sending ScreenDivider's window handle to dll
MODIFY DATA STRUCTURE ABOUT CSDFORM

CList is so complicate data strucutre, so I changed this CArray more
simple to use.

THIS CHANGE CAN BE IMPORTANT PROBLEM ! ! !
Add getting index from CSDWindow
Add showing/removing virtual window

Now, if the cursor of moving window is in titlebar, virtual window
should be show. And if the virtual window no need more, that will be removed.