test: Correct error messages for daemon use
shared: Update deserialize to return a size_t
shared: Call handle_message with correct size

Previously was calling with the amount read most recently instead of
with the client specified size.
shared: Add BuxtonString packing utility macro
shared: Add missed deserialize message return conversion
shared: Correct type being used by read
shared: Remove left over log messages
shared: Update deserialize message to take size as a size_t
shared: change serialization to use size_t

Had a few missing places where size_t wasn't being used to store
serialized data (and then had conversions when deserializing) that
could cause problems so switch to using size_t.
shared: Enable SMACK label serialization and storage

This change allows the serialization functions to support SMACK label
marshalling and unmarshalling for BuxtonData.