Added int* to method declarations to improve visibility of errors, and changed return type of WriteMessage
message_stream will now return appropriate status if WriteMessage encountered an error. byte_stream now passes int* to appropriate method calls. outgoing_string_value must match interface
reader_writer will now set int* to errno code if an error is encountered during read
implemented classes must match interfaces
removed unused method declaration
Merge pull request #22 from gonzogomez/master

Improved visibility to failures