gdk-pixbuf - more compilation woes with MSVC

[John Emmas <johne53 tiscali co uk>]

I recently noticed this newly introduced statement at line 616 of 
'gdk-pixbuf/io-jpeg.c':-

      density_str = g_strdup_printf ("%d", DPCM_TO_DPI (cinfo.X_density));

There's a similar statement, a few lines further down.  In 
'gdk-pixbuf/gdk-pixbuf-private.h' we define DPCM_TO_DPI like so:-

      #define DPCM_TO_DPI(value) ((int) round ((value) * 2.54))

Unfortunately, MSVC doesn't contain 'round()'.  Its closest equivalent 
function is probably 'floor()'.  Can this be fixed?

Also (while I'm at it) there's an unrelated problem at line 757 of 
'gdk-pixbuf/io-tiff.c':-

      guint16 codec = strtol (compression, NULL, 0);

Because we're building as 'C' (rather than C++) the variable 'codec' 
needs to get declared at the top of the function (along with all the 
other declarations).  I can enter these problems into Bugzilla if that's 
preferable.

John