Konvertierung von Eltree zu Lazarus.

TODOS:

1. elheader.pas
procedure TCustomElHeader.SetRightAlignedText(newValue : Boolean);

2. eltree
procedure TCustomElTree.WMRButtonUp(var Msg: TWMRButtonUp);
SendCancelMode(nil);

procedure TCustomElTree.SetRightAlignedText(newValue: Boolean);

code  hinzugefgt: 

1. eltree.pas
a)
procedure TCustomElTree.Resize;
begin
  //soner added Assigned(FHeader) and
b)  
procedure TCustomElTree.DefineHRange;

BUG von fpc: (ich glaube)
procedure TElTreeItems.Iterate;
