Log Message:
Update to 4.16.0.63.  Closes PR pkg/19924 by Greg A. Woods.

Changes since 4.16:
- Portability fixes.  Most important: work around a never-to-be-fixed
  bug in ncurses (the freely redistributable termcap/terminfo
  database).
- Various minor bug fixes.  Highlights:
  + use mkstemp to avoid a security loophole
  + avoid bad interaction between metakey and xterm mouse support
    in windows wider than 95 characters
  + handle symlinks better
  + obscure bug in text justification that could hang JOVE
  + misuse of stat that only misbehaved on LINUX