SummerOfCodeProposal AI Improvement Crab AI Manager

AI Manager

First version of this class is already written and committed to Wesnoth.

The purpose of this class is to act as a single point of contact between Wesnoth code and AI code and to manage AI lifecycle, thus avoiding any leaks and allowing AI hot-redeployment.

This class is used by Wesnoth in the following ways:

- to add, create AIs, or list all known AI types (aliases)

- to remove AIs

- to get active AI parameters

- to set active AI parameters

- to ask the AI to play its turn.

Also, this class is a factory for the AIs (at the moment, this functionality is used by master AIs who need additional AIs to be created)