Added method to get a duplicate of the internal Hash

[thorsteneckel]

This aims to avoid constructs like this:

attributes = {}
ldap.search_root_dse.each { |key, value|
  attributes[key] = value
}
attributes

Which now will look like:

ldap.search_root_dse.to_h

[HarlemSquirrel]

I like it! I think we should merge this in after our next patch release and include this in a minor release since it's a new feature.

[HarlemSquirrel]

Thank you!