OpenSystemsDevelopment / qpdf

Specifically, if a stream had its stream data replaced and had
indirect /Filter or /DecodeParms, it would result in non-silent loss
of data and/or internal error.

This is suitable for use as a Lambda layer in AWS, inclusion in a
docker container, or other places where a minimal binary distribution
is desired.

StreamDataProvider::provideStreamData now has a rich enough API for it
to effectively proxy to pipeStreamData.

I keep looking here to find out when I started requiring C++-11, and
now I will find the answer in the first place I look.

If a page contains a form XObject, also filter the form XObject and
remove its unreferenced resources.

Refactor removeUnreferencedResources to prepare for filtering form
XObjects.

fix-qdf assumes there is exactly one XRef stream and that it is at the
end of the file.

If the value of /CS in the inline image dictionary was is key in the
page's /Resource -> /ColorSpace dictionary, properly resolve it by
referencing the proper colorspace, and not just the name, in the
external image dictionary.

Allow exit status-based checking of whether a file is encrypted or
requires a password without necessarily supplying the correct
password. Useful for scripting.