Calculates and returns actual offset for this Parent
function IncForParent(Parent: TWinControl; Offset: Integer): Integer;
IncForParent calculates and returns offset for current Parent.
It stores offset for each parent it has applied so that offset increment is smart.
Parent is pointer to wincontrol components are placed onto.
Offset is number of pixels, for what user intends to place component off as it would be single one.
This method calculates offset depending on count of buffer's components and parent so that pasted components do not overlap existing ones.