Problem: growth of service objects.

[proofit404]

Usage / Story / Why

We give a lot more in development experience in comparison to

def action():
    state = {}
    a1s1(state)
    a1s2(state)
    return state

• state representation
• knowledge of who change what
• automatic logging of meaningful things
• history of execution (traceback with local variables will show only current stack)

classes allows us to:

• invertion of control by default

Follow up of #127 #208