[libpng17] Imported from libpng-1.7.0beta45.tar
[libpng17] Bump version to 1.7.0beta46
Bumper grab bag of pngvalid tests(+)
Endless hours of fun for the programmers in your family.  These tests
implement previously untested cases of libpng transforms; certain to
break within a couple of weeks(*).  Arrives in your home with one test
already broken!  Even better this patch includes a free $.42 value fix
for the broken test; we put the filler bytes into the alpha channel bag
in the wrong order, now we show what happens when it is done right!

(*) Manufacturer does not guarantee tests will break, some tests have
been known to continue to work for years.

(+) Tests are offered without warranty as to fitness for purpose or
correctness.  Tests may themselves not be correctly implemented and
failures in the tests may not equate to failures in libpng.

Manufactured in Dreary Orygun, see our website <error 404> for many
more chintzy lines of code, including some really gross hacks!

Signed-off-by: John Bowler <jbowler@acm.org>
[libpng17] Implement previously untested libpng transforms in pngvalid.c
[libpng17] Fixed byte order in 2-byte filler, in png_do_read_filler().
Merge branch 'libpng17' of /home/jbowler/src/libpng/libpng into libpng17