Removed -d ( --dir ) method of specifying directory. Instead the directory is now a mandatory argument.
The last specified argument will always be treated as the directory.

Consequently as the argument is now mandatory the current working directory is no longer used as a default
and so it must be specified manually if desired.
Bumped version number
remove unused --dir option in help
Added missing manditory command line option in help message for short options.
Merge pull request #4 from arfoll/cmd-arg-change

The specifying of the directory to be used for extraction is now mandatory. Consequently the current working directory is no longer used as a default.