OpenSystemsDevelopment / qpdf

All version operations are now fully aware of extension levels.

This file used to exercise a zero offset test case when qpdf would
visit every object in the file.  After the next commit, qpdf no longer
touches unreferenced objects, so a reference had to be added to
continue to have this file exercise the zero offset case.

For linearization tests where we are actually comparing the exact
output of the test with a known file, uncompress stream data so we can
see what's there.  This makes looking at future changes a little
easier.

Allowing users to subclass InputSource and Pipeline to read and write
from/to arbitrary sources provides the maximum flexibility for users
who want to read and write from other than files or memory.

Since sourceforce automatically displays README-what-to-download.txt,
it is no longer necessary for this to be the default file on
Windows.  Instead make one of the binary distributions the default on
Windows.

This makes it possible to use two different writers to write
linearized files from the same QPDF object.

This replaces a PDF from the wild that I didn't want to include in the
test suite but used to verify the original fix.

Previously only whitespace and comments did it.  This fix is needed
for object streams whose last object is a literal (name, integer,
real, string) not terminated by space or newline.

Use --encryption-file-password, if given, in addition to --password as
a source for passwords for files specified in --pages.

3.0.rc1

LARGE_FILE_TEST_PATH -> QPDF_LARGE_FILE_TEST_PATH
SKIP_TEST_COMPARE_IMAGES -> QPDF_SKIP_TEST_COMPARE_IMAGES