Update the client files to be consistent with the organization workflow.

• Add Locales.lua.
• Add Masque_Squarish_Vanilla.toc.
• Add Masque_Squarish_Wrath.toc.
• Update Masque_Squarish.toc.
  • Rename Masque_SiimpleSquare.toc to Masque_Squarish.toc.
• Update Skins.lua.
  • Rename Masque_SiimpleSquare.lua to Skins.lua.