fix memory leaks during PDF document creation

pdf_create_document leaks the trailer and in pdf-device.c many objects
are inserted into dictionaries using pdf_dict_puts and leaked instead
of using pdf_dict_puts_drop.
Fix 694093: add vertical variant of CJK fallback font.

Replace the DroidSansFallback TTF files with a TTC that has two fonts:
The original and a copy where the OpenType 'vert' substitution
lookup has been pre-applied by copying the uniXXXX.vert glyph data
to uniXXXX.