[Qt] New Qt patch - TCalendar implemented

[Felipe Monteiro de Carvalho]

Hi,

Did you update your sources recently? applying the patch showed some conflicts

Also, I don't like comments with questions (no-one will answer them in
the code, they should be instead discussed on the mailling lists)

+  {we have a bug in LCL when parent is TCustomCheckGroup, it doesn't
set sizes for items ?!? Width = 0 , Height = 0}

IMHO comments should be simple, stick to the point of why the code was
put there and inpersonal (so no need for signatures, svn will reveal
who wrote it if that matters).

And the HiddenButton issue seams to become an ugly hack on our
widgetset code .... maybe a solution in LCL should be made instead

Also, please note that we are now going to support Qt 4.2 too

So, when adding qt4 unit to new units see what I did on the other
units to add selectively qt4 or qt42 units

Further, there are some ifdefs for the mdi things. Is this unstable or
something like that? IMHO if they don't cause bugs we can just remove
the ifdefs and change to IFNDEF USE_QT_4_2

Also, please add IFDEFs around functions not available on Qt 4.2

thanks,
-- 
Felipe Monteiro de Carvalho