Allow parsing of message with 0 byte body.
Merge pull request #51 from hultqvist/master

Allow parsing of message with 0 byte body.
Cleaned up previous pull request a bit and added some commentary
Fixed compile warning by commenting out one-pass stuff that we don't use
Added a unit test for issue #51 and fixed it to actually work
Switch to using PBE SHA-256 + AES256 for encrypting private keys instead of SHA-1 + 3-key TripleDES
Added support for PostgreSQL-based certificate database

* Abstracted common SQL code in new class SqlCertificateDatabase.
* Fixed SQL to not use SQLite-only syntax (explicit lower() calls instead
  of COLLATE NOCASE, "IS NOT NULL" instead of just "NOT NULL")
* Fixed certificate loading to not depend on case of column names (some
  backends implicitly convert uppercase to lowercase unless the
  identifiers are quoted and return column names with different case than
  the one used in CREATE TABLE).
* Added NpgsqlCertificateDatabase class and tests.
Merge pull request #52 from fogzot/master

Added support for PostgreSQL-based certificate database
Modified the SqlCertificateDatabase abstraction a bit
Fixed the build for older NUnits
Added another ParseException .ctor
Started implementing TNEF support
Flushed out some more TnefPropertyTags (ugh, there are so many of them)
Flushed out a bunch more TnefPropertyTags
Oh, God, when will the hurting stop???
Fleshed out the remaining TnefPropertyTag fields
Roughly implemented TnefReader
Added sample code for encrypting and decrypting messages with S/MIME and PGP/MIME
Added OpenPgpContext.GetDecryptedStream() methods for use with inline PGP
Lots of work on the TNEF support... getting there, I think