Eli,

To get rid of an "unused macro" warning in the Cygwin-w32 build, I want 
to remove the definition of PIXEL_ALREADY_TYPEDEFED from image.c.  (It's 
defined in simx.h, which is included by xpm.h, on Cygwin.)  In the 
course of doing this, I decided to do some cleanup that you suggested in 
the discussion of bug#18302.  See the attached patch, not yet installed.

Question: Should PIXEL_ALREADY_TYPEDEFED be removed unconditionally, or 
is it needed in the MinGW build?

Ken