[Lazarus] OnMouseWheel[Down/Up] support in TControl (patch included)

[Luiz Americo Pereira Camara]

Mattias Gaertner wrote:
>> As can be seen on that report, it introduces a Delphi
>> incompatibility.
>>     
>
> It's not a Delphi, but a winapi incompatibility.
>   

No, it's a Delphi compatibility. I tested CM_MOUSEWHEEL, the equivalent 
message of LM_MOUSEWHEEL. Under Delphi XPos and YPos fields returns 
screen coordinates.
Furthermore, OnMouseWheel MousePos also is at screen coordinates.

Luiz