Merges and moves identical implementations to base

Both base-modules had identical implementation of Conversation.setup_request.
Moves two identical implementations to base

Conversation.init() had identical implementations in subclasses. Moved
this to base class which makes it easier to find, update and fix bugs.
Deduplication of classes

Moves identical classes to base-module
Merge pull request #6 from asheidan/refactor/deduplication

Deduplication