* Added reference documentation for command-line options

- Intentionally didn't document -o, -O and -n

  Offline mode is an attractive nuisance.

  -n is unlikely to be needed and can be spelled newest=true

- Removed -o, -O and -n from command help.

- Sorted options alphabetically in the reference doc and command help.

- Removed documentation of the log-level option.  It just confuses things.
  I seriously doubt that anyone uses it.