Hi everyone,

This patch adds clojure to guix. I have been interested in clojure's
syntax for vector [] and hash-map {} for a while, after watching the
introduction of clojure to lisper video. So, I decide to package it for
guix! Note that I follow the example in ldc and download tarballs needed
to run the tests. I have also used pandoc to build markdown files to
html.


Things I want to do but don't know if I should:

Should I add old version of clojure as well? Also, I have tried further
compile the jar to native executable using gcj. I think it works
although offically gcj supports up to java 1.5 while clojure is written
using java 1.6. The native executable takes 0.5s to 0.6s to start while
  time java -cp "$HOME/.guix-profile/share/java/clojure-1.8.0.jar" \    
            clojure.main --help'
takes 1 to 1.2 s to start on my laptop. Should we provide clojure-gcj
package?

Cheers,
Alex