Simplify constructors to handle multiple listeners at once

[davideas]

Simplify ALL constructors. The adapter should recognize which type of listener an Activity or a Fragment is implementing the events triggered by the User or by the adapter.
Give the possibility to Developers to decide which listeners to implement one by one.

Maybe pass 1 single parameter to represent all listeners that object belongs to, or use prefix-with methodology to set the listeners at startup.

[davideas]

This is experimental, but it's done in v5.0.0-b2.