Version 9.21 (2017-03-16)

This is the fifteenth full release in the stable 9.x series.

Highlights in this release include:
* pdfwrite now preserves annotations from input PDFs (where possible).
* The GhostXPS interpreter now provides the pdfwrite device with the data it requires to emit a ToUnicode CMap: thus allowing fully searchable PDFs to be created from XPS input (in the vast majority of cases).
* Ghostscript now allows the default color space for PDF transparency blends.
* The Ghostscript/GhostPDL configure script now has much better/fuller support for cross compiling.
* The tiffscaled and tiffscaled4 devices can now use ETS (Even Tone Screening)
* The toolbin/pdf_info.ps utility can now emit the PDF XML metadata.
* Ghostscript has a new scan converter available (currently optional, but will become the default in a near future release). It can be enabled by using the command line option: '-dSCANCONVERTERTYPE=2'. This new implementation provides vastly improved performance with large and complex paths.
* The usual round of bug fixes, compatibility changes, and incremental improvements.

(adam)