Minecraft wiki entry for The_Update_that_Changed_the_World, associated text: 1.7.4 brought players Twitch.tv broadcasting and the Chicken Jockey.
1.7.5 brought minigames to Realms servers.
1.7.6, 1.7.7, 1.7.8 and 1.7.9 brought internal changes necessary for future player name and skin infrastructure.
1.7.10 saw Realms extracted to its own library, so that updates to Realms would no longer require version upgrades.