Imported overlord solution

Joe/Sophia,
I spent this morning re-doing my level_up fork and branches. I believe it is correct now. Each task now has its own branch containing nothing other than changes pertinent to the task itself.

I'm resubmitting a code-review pull-request for overlord.

Zamir
This is a good illustration of why the messages are strange inside the class. A more fluent version of this would be `check_activation_code && activate_bomb`, only returning true and false.