Preserve name values in named email addresses for To, Cc, Reply-To

In v1.0.0 my mail(:reply_to) values were having their names gobbled.  I.e. "\"Russell Bevers\" <russell@example.com>" was becoming "russell@example.com".  I didn't like this because it was exposing my big, ugly, magical reply-to values (a la "message+27423348-3423-8888-2343-348134838823@foo.com") to the recipients unnecessarily.

In evaluating the gem I found it was because of the code in to_postmark_hash.  Here's a code patch that fixes it, hopefully in a desirable way.  All the spec tests pass...

Existing code that uses naked email addresses in unaffected, but those who want/use named email addresses the value is preserved.