Log Message:
Update to 3.280:

Version 3.28 - 12 May 2011

   - added an enhancement to the tiled-image compression method when compressing
     floating-point image using the standard (lossy) quantization method.  In
     cases where an image tile cannot be quantized,  The floating-point pixel values
     will be losslessly compressed with gzip before writing them to the tile-
     compressed file.  Previously, the uncompressed pixel values would have
     been written to the file, which obviously requires more disk space.

   - made significant internal changes to the structure of the tile compression
     and uncompression routines in imcompress.c to make them more modular and
     easier to maintain.

   - modified configure.in and configure to force it to build a Universal
     binary on Mac OS X.

   - modified the ffiter function in putcol.c to properly clean up allocated
     memory if an error occurs.

   - in quantize.c, when searching for the min and max values in a float array,
     initialize the max value to -FLT_MAX instead of FLT_MIN (and similarly
     for double array).