OpenSystemsDevelopment / qpdf

Add options to enable the raw encryption key to be directly shown or
specified. Thanks to Didier Stevens <didier.stevens@gmail.com> for the
idea and contribution of one implementation of this idea.

Fix comment, remove restriction that doesn't actually matter.

If the stream isn't filterable but we call getStreamData, throw a
regular exception instead of a logic error so that normal error
handling and reporting mechanisms will be used.

Initial implementation provided by Casey Rojas <crojas@infotechfl.com>
Some problems are fixed in a subsequent commit.

Tweak the message so that we inform the user that we are mitigating
data loss.

Avoid calling jpeg_mem_src and jpeg_mem_dest. The custom destination
manager writes to the pipeline in smaller chunks to avoid having the
whole image in memory at once. The source manager works directly with
the Buffer object. Using customer managers avoids use of memory source
and destination managers, which are not present in older versions of
libjpeg still in use by some Linux distributions.

The latter catches underflow/overflow.

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

While scanning the file looking for objects, limit the length of
tokens we allow. This prevents us from getting caught up in reading a
file character by character while digging through large streams.

A stray semicolon caused a condition to be incorrectly applied during
stream length recovery.

Pushing member variables into a nested class enables addition of new
member variables without breaking binary compatibility.