Version 1.31 released

Small update containing some fixes and an engine upgrade.

– [misc] Technical upgrade (new 3rd party libraries) also engine upgrade (small improvements like mute on focus lost).
– [misc] New buttons on main menu page (Discord, Website, etc).

– [fix] Rebels not progressing in the Birth of the Empire game mode. It also fixes your older saves.
– [fix] Crashes during Rename fleet when Delete key is pressed (it seems over the years no one ever tried to press that key, so the bug was unnoticed for so long :D)