v4.0.0

• Remove LibBabble dependency
• Prevent taint when dressing inspect target
  • MogIt previewing inspect target will still taint copy outfit.
  • Closes #31.
• Use SetItemRef callback for MogIt links
• Update main frame appearance
  • Hides portrait icon.
  • Changes Help button into an icon.
• Remove custom URL providers
  • Uses Wowhead for everything by default.
  • Addons may override using MogIt:SetURLProvider.
• Always load transmog sources from API
  • No longer stores items on disk, as API can retrieve all items.
  • Closes #34, #37, #39, #42.
• Remove unused library references
• Fix Chat Link not defaulting to chat if chat not active (#41)