- Add optional arguments to `init` method
   - `usage_lun` specify optional alternate output unit other than
     `stderr`
   - `version_lun` specify optional alternate version/license output
     unit other than `stdout`
   - `error_lun` specify optional alternate error info/message output
     unit other than `stderr`
 - Fixes #61
 - Will allow users to use MPI without `--help` or `--version` exploding
   with output when running on many MPI ranks

Fixes #61: More output control

Change tokenize behaviour: if the delimiter has higher number of chars
than the input string, only 1 token is returned containing the input
string instead of `char(0)` as previously.

Why:

More robust fail-safe when corner-cases happen, e.g. delimiter bigger
than input string.

Side effects:

Unknowns.