Display available disk space on disk on which the server pack will be generated/stored

Title

Something like

• Total: 500GB
• Free: 100GB

when not enough is available, do not allow generatioon. Check when trying to generate and warn if appropriate

changed milestone to %Version 5 - Peauty!!11!

added Feature label

assigned to @Griefed

mentioned in issue #154 (closed)

added Rejected label

closed