OpenSystemsDevelopment / qpdf

Reported in debian bug 902642

If we are unable to filter a page's content streams, don't attempt to
remove objects from the page's resource dictionary. Also provide a
command line option to suppress resource removal in case we ever need
this as a workaround for some bug or broken PDF files.

This is for testing the release process, particularly as it pertains
to AppImage creation.

Bump to an alpha release. This version is not being widely released
but is being used to push the new shared library version through the
debian packaging system and to test out github releases.

The Apache License version 2.0 is now the primary license for qpdf.
However, users may, at their option, continue to use Artistic version
2.0.

Most of the README files have been renamed. Refer to the new names.

There is no need for a --precheck-streams option. We can do the
precheck without imposing any penalty, only re-encoding the stream if
it fails the first time.

This commit adds several API methods that enable control over which
types of filters QPDF will attempt to decode. It also adds support for
/RunLengthDecode and /DCTDecode filters for both encoding and
decoding.

This is in preparation for implementing page groups.

Add a newline unconditionally before endstream even if a newline was
already written as part of the stream data.