OpenSystemsDevelopment / qpdf

Modernise constructors, make classes final, etc.

Remove remaining QPDFTokenizer private methods.
Remove QPDFTokenizer privileged access to Tokenizer.

Add new private Util.hh header to define inline functions and expose as
ordinary functions in QUtil.

Move all stream-specific methods to new class qpdf::Stream

Move all array-specific methods to new class qpdf::Array.

Move all dictionary specific methods to BaseDictionary. Create new subclass
Dictionary to allow QPDFObjectHandle to access the moved methods.

#1349 introduced a limit on the maximum size of arrays and dictionaries
contained in objects that generate errors during parsing, and #1354
reduced that limit to 5000 objects. However, the limit was only imposed
once a further error was encountered.

Stop adding objects to containers once the limit is reached.

Fixes oss-fuzz issue 398060137

Except for virtual functions to avoid the need for users to update code.

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

This requires a special build option.

Fixes oss-fuzz cases 376305073, 389974979 and 391974927.

Also, fix disabling of preserve_encryption to be ignore
stream_decode_level, but disable preserve_encryption if compress_streams is
false.

Fixes #1286

This reverts commit ff2a78f579ebdd06b417e34260a17dba06e71137, reversing
changes made to 8f54319f7a6514110f4b05cbbf1cb1c9fc8cb6a0.

This reverts commit 0e92cf6bf399249c603c3d0212e898fd29e71fcd, reversing
changes made to 7d34b89a69e8e89c098dd373442f7df809c28eff.

This reverts commit c648b9a018105a3c30b3e7f3c5f8a058d3ddd92c, reversing
changes made to 12b67a3227df6b6df3a4f5f098e11cce173ff7d5.

Also, make obj_cache private and rename to table.