Add an optional postDeserialize parameter to ProcessRequest. This allows users to perform extra steps before allowing the message to be seen by the registered message handler. Non-breaking change.

Merge pull request #1 from ananthonline/feature-protobuf-gen

* Fix a bug where the wrong tag (Request.Tag instead of Response.Tag) was being written to the response stream.

Add global:: to all using statements generated by Postal

Added protobuf generation.

Bump version to 1.3.6 to fix builtInTypeReplacements bug.

Re-order builtInTypeReplacements so that the longer typenames (uint, ushort) come before the shorter version (int, short). This prevents erroneous multiple replacements.

Fixed issue that caused tags to overflow, rendering messages un-identifiable. Fixed and bumped version to 1.3.5

Add generation of unique message tags based on the type string. This makes it possible to uniquely identify an incoming message. A future commit will make it possible to process requests across more than one Postal file in your project.

Add Tag property to IResponse

* Exposed _messageRequestTypes and _messageResponseTypes as ReadOnlyDictionary, enabling meaningful extension methods to be written that understand how to resolve raw messages to their final types.

* Separating IRequest and IResponse interface into their own assembly/Nuget package.

Added the following features:

Added extension methods for messages, so we can call them in true RPC style.

Fixed a typo in CodeDOM generation that was causing attribute parameters to be generated the wrong way.