Merge branch 'tr/die_errno'

Merge branch 'tr/die_errno'

* tr/die_errno:
  Use die_errno() instead of die() when checking syscalls
  Convert existing die(..., strerror(errno)) to die_errno()
  die_errno(): double % in strerror() output just in case
  Introduce die_errno() that appends strerror(errno) to die()