* Added overload constructor (c++11 only) taking iteratable object.
It would be easier to use std::string, std::array etc to construct
a message now. Making it a draft for now in case it is too greedy
and needs to be more specialize.
* Added equal and not euqal operator to message_t as a recommended
and expected way of comparing objects in C++.
* deprecated C style equal method as operator== should be used instead
(point above).
* Added message_t test covering all available message_t's constructors
