OpenSystemsDevelopment / qpdf

Simplify QPDFObjectHandle::isPageObject

Change QUtil::read_file_into_string to work with pipes (fixes #1010)

Check for missing mediaboxes

Maintain links to foreign pages when copying foreign objects (fixes #1003)

Remove use of non-standard `char_traits<unsigned char>` from Pl_Buffer

Ensure that links to foreign pages are not broken provided that the page is
subsequently copied.

… object (fixes #1011)

`basic_string<unsigned char>` implies use of
`char_traits<unsigned char>`.

This char_traits specialization is not standard C++, and will be
removed from LibC++ as of LLVM 18. To ensure continued LibC++
compatibility it needs to be removed.

There are two possible replacements here: `std::string` (e.g.
`std::basic_string<char>`), or `std::vector<unsigned char>`.

I have opted for vector since this code is dealing with a binary
buffer; though probably either way is fine (why does C++ even have
strings anyway??).

https://github.com/qpdf/qpdf/issues/1024

Fix typo in manual

Fix QPDFObjectHandle::disconnect (partially fixes #1011)

Fix formatting in library.rst

Split QPDF::readObject into readTrailer, readObject and readObjectInStream

 Add new private method QPDF::insertReconstructedXrefEntry

Add doxygen files to .gitignore