Support better message config for Giraph

There are various different options for sending messages in Giraph:

• whether there is going to be a combiner
• MessageEncodeAndStoreType to be used
• message factory
• etc

If you want different properties in different iterations, currently you can set some of them in master through SuperstepClasses, which are then sent to all the workers, which then use MessageStoreFactory (for example - InMemoryWithPrimitivesMessageStoreFactory)
Some of the properties are missing there, and so cannot be changed at all (like message factory/MessageEncodeAndStoreType)