Individual tasks for every thread (Fixed #13)

Now WhatsBotThread is a trait (instead abstract class).
Class' static property => Every thread (inheriting from model) will
SHARE the property.
Trait's static property => Every thread that uses the trait will have
his own property.

If thread don't use WhatsBotThread, we put a flag into $Thread array,
that says 'Don't try to get tasks!' xD