OpenSystemsDevelopment / qpdf

Removing it was ABI-breaking. I must have done it forgetting Pl_DCT.hh
was in the public API.

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

Fixes oss-fuzz case 394129398.

Issue arose from chaining multiple runlength filters and inflating a
compressed stream of ~100 bytes to several gigabytes.

There is no obvious fix without imposing an arbitrary implementation limit
and therefore potentially excluding valid PDF files.

This requires a special build option.

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

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

Also, tidy pipeline constructors and make subclasses final where possible.

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

Also, delay adjustments for compressed objects until needed by
linearization checks.

Temporarily disable 3 specific-bugs tests. Remove 'xref size mismatch'
test.

Also, when recovering trailer from xref streams, pick the last valid
trailer encountered rather than the first.

Fix #1242

Tidy QPDF_Stream

Ensure QPDF m->all_pages and invalid_page_found are reset if
getAllPagesInternal throws an exception.

Fixes fuzz case 71624.