Low Hanging Fruits

Features

• xbow:combine
• xbow:categorize and xbow:label
• xbow:for-each-index
  • xbow:sequence-for-each-index
  • xbow:array-for-each-index
• xbow:array-fill
• xbow:some, xbow:none, xbow:all
• shorter syntax for xbow:pluck
• xbow:get-type checks for arrays and maps too
• improve documentation