New configuration

• $wgAchievementBadgesAchievementFallbackIcon - This is the path to the fallback icons that displays in Special:Achievements.
• $wgAchievementBadgesReplaceEchoThankYouEdit - When this is set to true, the edit milestone notifications offered by Echo will be not sent.
• $wgAchievementBadgesDisabledAchievements - This is a list contains keys of achievements that should be unregistered. Wiki administrators can use this to disable a built-in achievement.

Enhancements

• Add new achievements:
  • contribs-{sun,mon,tues,wednes,thurs,fri,satur}day
  • create-page
  • edit-page
  • edit-size
  • enable-achievement-badges
  • long-user-page
  • sign-up
  • visual-edit
• Changes in Special:Achievements:
  • Add icon, body text and timestamp to each achievement.
  • Add an animation.
• Log achievements to Special:Log and show on Special:Achievements.
• Add a icon to BetaFeatures preference and Echo notifications.
• Link to the achievement fragment from notification.
• Add experimental Special:ShareAchievementBadge.

Bug Fixes

• Do not allow system users to achieve achievements.
• Suppress Echo's welcome notification when it is replaced with the sign-up achievement.
• Fix duplicated items on Special:Achievements
• Do not allow user who disables AB to earn achievement

Developer changes

• Hook calling uses new HookContainer.
• Add SpecialAchievementsBeforeGetEarned Hook.

Achievement registering changes

• New properties:
  • type - There is now two type: 'instant' and 'stats'. Read extension.json for details.
  • priority - This is used to ordering on Special:Achievements. (default: 1000)

Other changes

• Introduce Quibble tests.
• Store loggers in classes as a member variable.
• Use LocalUserCreatedHook instead of AddNewAccountHook
• Use a configuration variable and the ExtensionFunction to register achievements.