Extend ReaderStateQueries with Enumerable mixin.

I felt a little bit uncomfortable in ReaderStateQuerie(s) handling. With Enumerable accessing ReaderStateQueries becomes more intuitive, e.g.:

```ruby
queries = Smartcard::PCSC::ReaderStateQueries.new(readers.size)
queries.each_with_index do |q, i|
  q.reader_name = readers[i]
  q.current_state = :empty
end
# ...
queries.select { |q| q.event_state.include? :present }.each do |query|
  # do stuff on readers with present cards
end
```

I've also increased version number.

cheers
--alex