Module manager, version checker, updater

[snixtho]

Features:

• [ ] Ability to configure enabled and disabled modules. Disabled modules should not be enabled on startup.
• [ ] Installation of modules from the online module repository.
• [ ] Installation of modules from the local file system.
• [ ] Ability to update modules from the online module repository. Automatic updates as an option. No application restart required for this.
• [ ] In-game UI to browse and manage modules.