for supporting WindowsCE.

WindowsCE does not provide the "tm" structure.

and merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.

from pngwrite.c

(Contributed by Philip Lowman)

in pngwutil.c

Changed "=" to " = " where needed.

Changed "=" to " = ".

in png_handle_sPLT().

to check info_ptr members instead of the contents of the returned parameters.

to add a test for user passing a 16-bit height varible to png_get_IHDR()
which causes an overflow into the high bytes of the width variable.

and mentioned use of 2-space indentation in macro definitions in
the libpng style guide.