Integrated updater

[wipe2238]

Updater integration was best thing which happened in r4xx, it gonna be fun to roll own version :fireworks:

Few things i remember from toying with it years back

• duplication issues instead of using filename to decide if file is link or not, make them tiny .ini files which holds all data that can be also useful for some other tasks, eg server requesting file deletion
• it was damn boring to look at

Additional stuff which i'd like to have, that way or another

• [ ] bootstrap very-mini-updater; all it have to do is to get only latest client only and then launch it servers loves to pre-release their clients before session starts, that could be a minimal example how to do such thing
• [ ] allow update screen customization for starters, let it be something simple, like background/font color, as that's just numbers