OpenSystemsDevelopment / qpdf

Replaced raw shared pointers with std::string for `infilename` to improve simplicity and readability. Added a boolean `empty_input` flag to explicitly track empty input cases. Adjusted related logic and function calls accordingly for consistency.

Replaced shared_ptr<char> with std::string for `outfilename` in QPDFJob, simplifying its usage and reducing unnecessary memory management overhead. Updated related conditional checks and logic to align with the updated type. These changes improve code readability and maintainability.

Simplified checks for empty containers and strings across the codebase using the `.empty()` method. This improves code readability and adheres to best practices for checking emptiness.

Converted multiple occurrences of `count()` to `contains()` throughout the codebase where the goal was to check key existence in containers. This improves code readability and aligns with modern C++ practices, particularly with C++20, making the intent more explicit and potentially aiding performance.

Replace repeated key checks with `want_key` lambda for clarity and maintainability. Transition `Pl_String` from shared to unique ownership to reflect intent and improve resource management. No functional changes introduced.

Consolidate and replace inline JSON schema strings with static constexpr constants for better organization and maintainability. Functionality remains unchanged.

Centralize JSON schema dictionary member addition by introducing `add_if_want_key`. This reduces redundancy and improves maintainability by consolidating repeated logic. No changes to functionality were made.

Replaces repetitive key-check conditions with a reusable lambda function `want_key`, improving code readability and maintainability. Simplifies logic across multiple conditional sections in `QPDFJob.cc`.

Replaced `else if` chains with standalone `if` statements for clarity. Updated conditional checks with modern coding practices, such as using `.contains()` instead of `.count()`. These changes enhance code maintainability and ensure better style consistency.

Simplified code by removing redundant `this` qualifiers where they are not essential, improving readability and alignment with coding standards. No changes were made to functionality.

Thanks to github user @cdosborn for the basic enhancement.

Also, silently fix any angle that is a multiple of 90.

... to remove the /Root /StructTreeRoot and /MarkInfo entries.

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

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

This requires a special build option.

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

Add new commands --remove-metadata and --remove-info

A file that has Widget annotations that can't be mapped back to form
fields would crash qpdf json.

Accept --file and --range as named parameters in additional to
allowing positional arguments. This is in preparation for adding
additional flags.

The check for the number of items was in the wrong place.

Rather than adding yet another flag that is almost never useful on its
own, just have --remove-restrictions disable digital signatures. The
operations are still separate in the API.