Always prefer the rfc2184-encoded parameters over non-encoded parameters of the same name

Fixes issue #24
Moved all nuget files to a nuget directory
Added MimeEntity.Load() methods that load from a System.Net.WebResponse

Potential fix for issue #26
Moved the sqlite3.dll back to lib
Moved MimeEntity.Register() to ParserOptions.RegisterMimeType()
Cleaned up ParserOptions a bit
MimePart/Entity constructor with content type.
Merge pull request #27 from hultqvist/master

MimePart/Entity constructor with content type.
Minor cleanup to previous commit
Replaced MimeEntity.Load(WebResponse) with MimeEntity.Load(ContentType,Stream)

This patch better reflects what is needed in issue #26
updated docs
Bumped version to 0.19.0.0
Adding public MailboxAddress parser.
Merge pull request #28 from hultqvist/master

Adding public MailboxAddress parser.
Expanded on previous pull request and documented the API additions
Fixed InternetAddress Parse/TryParse semantics to be consistent with the BCL
Improved documentation.
More doc updates.
Don't forget to add a newline at the end of the Sender: header

Fixes issue #29
When encoding an address list, don't forget to separate addresses with a ','

Fixes issue #30