Log Message:
jdebp-redo: update to 1.5. Changes:

- What OS/2 and Win32 support was there has been removed; this is now a
  POSIX-only program.
- redo now handles jobserver options correctly in MAKEFLAGS created
  by BSD make.
- A bug has been fixed in the jobserver that was permitting a deadlock
  condition. A running redo now never yields its original slot.
- redo now takes out a shared lock on prerequisites lists whilst
  processing them.