Message object creation - refactoring

[tkgauri]

No description provided.

[gugod]

I briefly brought this up to @tkgauri in a meeting, the though behind this is to have a "message builder" with more intuitive usage. The main intention is to let users read a bit of API documentation, and be able to directly translate that knowledge as the way to use SDK -- instead of having to learn the same thing twice with different flavor.