Update from 5.1.16 -> 5.1.17

• src/pdfdrv.c: Fixed crash in PDF when using patterns with PDF-1.4.
• Xbae/Xbae/Create.c: Backported font width fixes.
• src/x11drv.c: Backported page frame fix.
• src/: Tab.c, XMgrace.ad, xmgrace.c, Tab.h: Backported tabFontList changes.
• src/pdfdrv.c: Changed default PDF dpi to 300.

PR: 72197
Submitted by: Shuhei Amakawa <sa264@cam.ac.uk>