Log Message:
Update GraphicsMagick to 1.3.11.

1.3.11 (February 21, 2010)
==========================

Security Fixes:

  * Fixed array underflow on systems using signed char which could
    result in a program crash due to extended characters in filenames
    or in certain file formats.

Bug fixes:

  * Fixed array underflow on systems using signed char which could
    result in a program crash due to extended characters in filenames
    or in certain file formats.

New Features:

  * Added a -thumbnail command to 'convert' and 'mogrify'.  This is a
    faster way to scale down the image when speed is a primary
    concern.

  * Added a -extent command to 'convert' and 'mogrify' which
    composites the image on top of a backing canvas image of solid
    color.

  * Added support for -compose to the 'convert' and 'mogrify', which
    were documented to support it (but did not).

Feature improvements:

  * None

Performance Improvements:

  * Requests for 'Over' and 'Atop' composition are converted to a
    request for the (faster) 'Copy' composition when both images are
    opaque.

Behavior Changes:

  * None