OpenSystemsDevelopment / qpdf

Having it at compile time breaks cross-compilation and isn't really
right anyway.

Change QPDF::copyForeignObject to return a null object when called wi…

Test for missing object before accessing obj_copier.object_map.

Fix exit code when an input other than the primary input generates wa…

m-holger's fix is better

This reverts commit fa3cdaf1b46dcbb583393f93a02f89207ba21a88.

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)

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