OpenSystemsDevelopment / qpdf

Also remove linearization from qpdf-manual.pdf. It's a small file, and
removing the dependency on the qpdf executable significantly shortens
build times.

Add a new make target that installs the qpdf libraries without
executables or documentation.

This solves
  libtool: compile: unable to infer tagged configuration
  libtool:   error: specify a tag with '--tag'
build issues when using toolchain that prevents libtools
inference rules from working correctly (e.g. ccache).

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.

Use autoconf rather than ifdefs to determine what format string to use
for long long.

For wildcard expansion to work properly with the msvc binary, it is
necessary to link with setargv.obj or wsetargv.obj, depending on
whether wmain is in use.

If QPDF_CRYPTO_PROVIDER is set, just run the tests for the given
provider. This is to support cases of running the entire test suite
for each provider. If QPDF_CRYPTO_PROVIDER is not set, run the tests
that exercise the cyrpto provider for each available provider.

I don't want to maintain them or make anyone think they should be used.

libtool make install already works this way.

Specify qpdf libraries before external ones.
Specify LDFLAGS before libraries.
This should eliminate remaining cases of qpdf builds favoring
previously installed versions.

Resolve link error on cygwin

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

Slightly improve memory cleanup in Pl_DCT
Make it easier to test with valgrind

Don't try to install HTML or PDF documentation if we're not building
docs.

Without this, qpdf executables work only on Vista or newer.

Fixes #35

Also separate C and C++ warning flags.

Make --enable-werror work properly on msvc, handle extra warnings
flags for msvc in configure.ac instead of hardcoding into
make/msvc.mk, separate warnings flags into WFLAGS in autoconf.mk to
avoid duplication and to make it easier to override.

Some distributions (like debian) don't want .la files to be installed,
but the responsibility for doing this should like in the packaging,
not in qpdf itself.

Place user-specified CPPFLAGS and LDFLAGS later so that user-specified
non-standard paths that have old versions of qpdf don't cause the
build to fail.

Update the build to support new external-libs layout, and autoconf
options to specify windows word size.  Split make_windows_releases
into multiple scripts.

Significantly improve the code's use of off_t for file offsets, size_t
for memory sizes, and integer types in cases where there has to be
compatibility with external interfaces.  Rework sections of the code
that would have prevented qpdf from working on files larger than 2 (or
maybe 4) GB in size.

For ELF systems, turn on versioned symbols by default, and add a
configure option to enable or disable them.