shinarit/wiz — pull request #5 by susu (2012-06-29 21:08:39+00:00)
Title: In case of nonexistent argument prints the usage

In case of nonexistent arg it threw an ```std::logic_error```. Seems like it caused by null ```optarg``` variable on string construction.

Erroneous printout on my ArchLinux, GCC 4.7.0:
```
$ ./wiz --help
./wiz: unrecognized option '--help'
terminate called after throwing an instance of 'std::logic_error'
what(): basic_string::_S_construct null not valid
Aborted
```