[Lazarus] SetScrollInfo

[Hans-Peter Diettrich]

TWin32WidgetSet.SetScrollInfo modifies the content of the ScrollInfo
     ScrollInfo.nMax := Max(ScrollInfo.nMin, ScrollInfo.nMax - 1);
i.e. nMax is typically decremented by 1, with *every* new call!

IMO this is *not* a desireable behaviour.

Iff there exists a difference between the LCL and Win32 interpretation 
of the TScrollInfo record, this should be handled in a way that does not 
invalidate the user supplied information.

DoDi