E1S9.1: Add cave ambience sound source
E1S12: Add more LOCK_VIEW/UNLOCK_VIEW pairs
Add [mute_sound_effects] WML action
E2S0: Replace music with a single cave ambience sound source
Do not redefine the Khalifate Falcon unit type and movetype on Wesnoth 1.11.8+
E2S0: Prose review