IEnumerable<string> Option ignores duplicate values

[Crauzer]

Passing the following -s "one" "two" "three" "three" "three" to an option that's an IEnumerable<string> will yield only the first 3 strings and ignore the last 2.

[rmunn]

A bugfix for this issue has been merged into the develop branch, and will eventually be released in version 2.9.0. That release was delayed by several months by an outdated NuGet API key, but #733 takes care of that problem, so hopefully the release with that bugfix will be available soon.