title: Remove #inst and #uuid literals in clojure
body: <p>I have a UUID and java util date which get literals as #uuid and #inst, how do I specify the uuid or date without referencing the literals themselves?
  clj-json does not like dealing with them and ends up throwing an error when I try generate-string </p>
  
  <pre><code>{:timestamp (java.util.Date.)}
  ;{:timestamp #inst "2013-05-17T13:45:24.095-00:00"}
  
  ;but as a string the date changes format
  {:timestamp (str (java.util.Date.))}
  {:timestamp "Fri May 17 09:45:44 EDT 2013"}
  
  (json/generate-string {:uuid (java.util.UUID/randomUUID)}) 
  ;#uuid "d66cf77f-13b6-4291-95cd-c2bb40aa36b3"
  
  java.lang.Exception: Cannot generate d66cf77f-13b6-4291-95cd-c2bb40aa36b3
  JsonExt.java:96 clj_json.JsonExt$Generator.generate
  JsonExt.java:83 clj_json.JsonExt$Generator.generate
  JsonExt.java:103 clj_json.JsonExt.generate
  core.clj:18 clj-json.core/generate-to-writer
  core.clj:26 clj-json.core/generate-string
  NO_SOURCE_FILE:32 myapp.handler/eval8390
  </code></pre>