to libpng-1.6.0beta05 versions.

should not require itself.

to be prefixed (suggested by Reuben Hawkins).  This is work in progress that
breaks some non-configure builds.

Also eliminated PNG_CONST_DATA, which is apparently not needed but we
can't be sure until it is gone.

to the background parameter of png_image_finish_read. The --background
option is now done automagically only when required, so that commandline
option no longer exists.

Added color-tests, silent-rules (Not yet implemented in Makefile.am) and
version checking to configure.ac

grayscale), and renamed three whose names were inconsistent with those in
pngsuite/README.txt.

This version of autogen.sh attempts to dissuade people from running it when
it is not, or should not, be necessary.

(C. Yapp).

in CMakeLists.txt

instead of running tools one-by-one.

Also some layout regularization and removal of introduced tab characters
(replaced with 3-character indentation).  Obsolete macros identified by
autoupdate have been removed; the replacements are all in 2.59 so
the pre-req hasn't been changed.  --enable-werror checks for support
for -Werror (or the given argument) in the compiler.  This mimics the
gcc configure option by allowing -Werror to be turned on safely; without
the option the tests written in configure itself fail compilation because
they cause compiler warnings.

compiler issues slightly different warnings from those issued by the
current vesions of GCC. This eliminates those warnings by
adding/removing casts and small code rewrites.

This is an initial version for review; the documentation has not yet been
updated.

changes some of the macro definitions in png.h, app code may need
corresponding changes.

truncated (bug introduced in libpng-1.5.3beta05).

and cleaned up some indentation problems.

when png_uint_32 and unsigned long are of different sizes.

those uses of png_memcpy that were doing a simple assignment to assignments
(all those cases where the thing being copied is a non-array C L-value.)
Added some error checking to png_set_*() routines and removed the
reference to the non-exported function png_memcpy() from example.c. Fixed
the Visual C 64-bit build - it requires jmp_buf to be aligned, but it had
become misaligned.

to the proper location in configure.ac (Gilles Espinasse).

Added new "png_structrp" typedef. Because of the
way libpng works both png_info and png_struct are always accessed via a
single pointer.  This means adding C99 'restrict' to the pointer gives
the compiler some opportunity to optimize the code.  This change allows that.

Previously it was disabled whenever internal fixed point arithmetic was
selected, which meant it didn't exist even on systems where FP was available
but not preferred.

and only calls one other internal function and memset.

These changes alter how the tricky allocation of the initial png_struct and
png_info structures are handled. png_info is now handled in pretty much the
same way as everything else, except that the allocations handle NULL return
silently.  png_struct is changed in a similar way on allocation and on
deallocation a 'safety' error handler is put in place (which should never
be required).  The error handler itself is changed to permit mismatches
in the application and libpng error buffer size; however, this means a
silent change to the API to return the jmp_buf if the size doesn't match
the size from the libpng compilation; libpng now allocates the memory and
this may fail.  Overall these changes result in slight code size
reductions; however, this is a reduction in code that is always executed
so is particularly valuable.  Overall on a 64-bit system the libpng DLL
decreases in code size by 1733 bytes.  pngerror.o increases in size by
about 465 bytes because of the new functionality.