MagickLib requirement

[Daniel J Sebald]

Carnë,

With the following changeset:

http://hg.savannah.gnu.org/hgweb/octave/rev/ba79ba4e83ab

my version of tools is just a little too old so that I get the following 
erros:

../../octave/libinterp/dldfcn/__magick_read__.cc: In function 
'octave_value magick_to_octave_value(const MagickLib::CompressionType&)':
../../octave/libinterp/dldfcn/__magick_read__.cc:1484:12: error: 
'LZMACompression' is not a member of 'Magick'
../../octave/libinterp/dldfcn/__magick_read__.cc:1486:12: error: 
'JPEG2000Compression' is not a member of 'Magick'
../../octave/libinterp/dldfcn/__magick_read__.cc:1488:12: error: 
'JBIG1Compression' is not a member of 'Magick'
../../octave/libinterp/dldfcn/__magick_read__.cc:1490:12: error: 
'JBIG2Compression' is not a member of 'Magick'

Is Octave meant to be compilable with older versions of ImageMagick 
library?  I.e., create some functions like

#if IMAGEMAGICVERSION < 6.6.??
void LZMACompression ()
{
  error ("Requires ImageMagick version 6.??.?? or higher");
}
void JPEG2000Compression ()
{
  error ("Requires ImageMagick version 6.??.?? or higher");
}
etc.
#endif

Or is the expectation that ImageMagick should just be up to near the 
most recent version?

Dan