OpenSystemsDevelopment / qpdf

Also add debugging information so we can save time if $^O used in
GitHub Actions changes again.

This is necessary in case paths contain colons on Windows.

Fix build against a standard zopfli install

Fix the logic to accept a top-level `zopfli.h` header, as that is
the location used by upstream's build system.

Removing it was ABI-breaking. I must have done it forgetting Pl_DCT.hh
was in the public API.

This improves indentation of long strings. This commit also fixes some
trailing whitespace in ChangeLog.

Draft release notes

Refine QPDFParser error handling

Reduce the container size for which a single bad token will cause a failure
from 100,000 to 5,000.

Count missing dictionary keys as errors.

In Pl_RunLength apply memory limit before and after decoding

Apply sanity checks on SF_FlateLzwDecode parameters

If a flate memory limit is set, reject decode parameters that would cause
the limit to be exceeded and treat stream as unfilterable.

Fixes oss-fuzz issue 394463491

The stream filter is only used if the stream is filterable, therefore
there is no point continuing to set decode parameters once it is recognized
that the stream is not filterable.

Fix bugs found during fuzzing

Fail if a bad token is encountered while parsing an array or dictionary
with more than 100,000 elements.

Fixes oss-fuzz case 388571629.

Fixes oss-fuzz case 394129398.

Issue arose from chaining multiple runlength filters and inflating a
compressed stream of ~100 bytes to several gigabytes.

There is no obvious fix without imposing an arbitrary implementation limit
and therefore potentially excluding valid PDF files.

Add zopfli support

This requires a special build option.

Fix qdf output file

jidanni cli.rst update

(So folks working offline won't go for hours dreaming they can overlay *.txt files, until after the finish writing the txt file, and try it, and it doesn't work.)

Update copyrights

Fix bugs found during fuzzing

Check for direct outline items.

Fixes oss-fuzz case 	389339260.

Fixes oss-fuzz cases 376305073, 389974979 and 391974927.