fd/options — pull request #1 by serussell (2012-12-15 16:34:04+00:00)
Title: Adds default options

I've added support for default options in the spec, such that:

...
arg=5 -a= Some argument
...
opts, err := spec.Interpret([]string{"xyz"}, []string{})
opts.GetInt("arg") == 5
opts, err := spec.Interpret([]string{"xyz", "-a=2"}, []string{})
opts.GetInt("arg") == 2