Find the Ten Most Frequent Words in a Text

http://onlamp.com/pub/a/onlamp/2007/07/12/introduction-to-haskell-pure-functions.html
introduces functional programming in Haskell with an application that finds the
ten most frequent words in a text. Convert this to Clojure. Return the pairs of
the ten words with their frequencies. Test with Emma by Jane Austen 
found as emma.txt on our site. Include timing.

You might use a java.util.StringTokenzier to break the string read from the 
file into tokens.  The second arugment is a string of separator characters. A 
StringTokenizer has hasMoreTokens and nextToken methods.  Clojure has a 
split-with method that may be used to split off lists of equal words.