Mweb 983

@nandy-andy @rogatty Guys, this is a script mostly written by Rafał - please code review it and we could test it when it reaches QA column. Adding @aquilax here if he doesn't mind taking a look :) :8ball: :snowman: :bird:
Some of those variables are being set by Chef on every machine in `/etc/environment` file. It looks dirty to have them here. But since we want to run this script only once we can leave it like that and create a ticket to clean it after Mercury or next time when we'll need to use this script again.