Adjust joerg's patches in a way that fixes the gcc build and hopefully
doesn't rebreak the clang build. (sigh, C++)
Solaris, Mingw32 & OS X prior to 10.7 are missing strnlen, so provide an
implementation.  Sent request for similar fix upstream.
add strnlen for platforms missing it in textproc/mdocml
Update to 6.8.8.1:

2013-12-30  6.8.8-1 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.8-1, SVN revision 14087.

2013-12-27  6.8.8-1 Cristy  <quetzlzacatenango@image...>
  * Support points argument for draw MSL element.
  * Fix misplaced closing parenthesis for strncmp() call in magick/xml-tree.c.
  * The -page option now correctly sets the image page offset (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24701).
  * The -evaluate-sequence sum returns a proper alpha channel now (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24704).

2013-12-26  6.8.8-1 Dirk Lemstra <dirk@snakeware...>
  * Added support for reading zip compressed PSD files. (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24676).

2013-12-25  6.8.8-0 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.8-0, SVN revision 14027.

2013-12-23  6.8.8-0 Cristy  <quetzlzacatenango@image...>
  * Blurring with transparency no longer returns a halo (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24665).
  * Eliminate ICC profile memory leak for JP2 coder (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=2&t=24679).

2012-12-21  6.8.8-0 Dirk Lemstra <dirk@snakeware...>
  * Made librsvg the default svg library for the windows distribution.

2013-12-10  6.8.7-10 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.7-10, SVN revision 13965.

2013-12-10  6.8.7-10  SiuChi Chan  <...>
  * Fix crash when using -resize with GPU acceleration (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24603).

2013-12-08  6.8.7-9 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.7-9, SVN revision 13950.

2013-12-05  6.8.7-9  SiuChi Chan  <...>
  * Silence warning related to GPU memory issues.
  * Check if OpenCL is disabled in checkOpenCLEnvironment() method.
  * Turn off OpenCL path for Intel OpenCL to avoid crash when not enough memory.
  * Fixed a bug for OpenCL convolution.
  * Reduce compiler warnings.

2013-12-03  6.8.7-9 Glenn Randers-Pehrson <glennrp@image...>
  * Fixed bug in coders/png.c that caused -define png:color-type=0 to
    fail (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=24568).

2013-11-30  6.8.7-9 Dirk Lemstra <dirk@snakeware...>
  * Fixed bug in automatic selection of OpenCL device (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24542).
  * Fixed transparency for 32 bits BMP.

2013-11-28  6.8.7-9 Cristy  <quetzlzacatenango@image...>
  * The -type bilevel option sometimes returned an all white image (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24444).
  * Check blue channel threshold for -solarize option (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24473).

2013-11-27  6.8.7-8 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.7-8, SVN revision 13850.

2013-11-27  6.8.7-8  SiuChi Chan  <...>
  * Add an OpenCL-accelerated analog of AddNoiseImage().

2013-11-23  6.8.7-7 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.7-7, SVN revision 13827.

2013-11-23  6.8.7-7  SiuChi Chan  <...>
  * Simplified interface to initialize the OpenCL environment.
  * Automatic OpenCL device selection algorithm.
  * Support ModulateImage() acceleration.
  * Reduce the memory requirement for accelerated blur and unsharp mask.

2013-11-16  6.8.7-6 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.7-6, SVN revision 13767.

2013-11-14  6.8.7-6 Cristy  <quetzlzacatenango@image...>
  * Fix possible memory corruption when writing PSD images (bug report from
    Justin Grant).
  * Constrain color reduction acceleration to positive integers (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=24459).
  * fx:maxima.a now returns the alpha value rather than opacity (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24461).

2013-11-08  6.8.7-5 Cristy  <quetzlzacatenango@image...>
  * New version 6.8.7-5, SVN revision 13682.

2013-11-03  6.8.7-5 Cristy  <quetzlzacatenango@image...>
  * The jpeg:extent option no longer returns double-free exception (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24366).
  * Turn off arch-specific optimisations (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24353).
  * The -type bilevel option no longer returns black image (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=24394).

2013-11-03  6.8.7-5 Dirk Lemstra <dirk@snakeware...>
  * Added support for pangocairo to the windows distribution.
  * Added /OpenCL option to configure.exe to enable OpenCL.

2013-10-31  6.8.7-5 Glenn Randers-Pehrson <glennrp@image...>
  * Fixed cut-and-paste error in version.c that caused the "png" delegate
    to be listed twice by the "convert -version" command.
Updated graphics/ImageMagick to 6.8.8.1
Needs xgettext, seen in freebsd build.