+popen is a subprocess library for Clojure.
+`(popen ["ls" "-a" "/tmp"] :redirect false :dir nil)`
+ Open a child process. Optional parameters are `redirect` to redirect stderr
+ to stdout and `dir` to start with a different working directory. Returns the
+`(popen* ["ls" "-a" "/tmp"] :redirect false :dir nil)`
+ Same as `popen`, returns the process stdout stream.
+ Return the standard output of the process (for reading).
+ Return the standard error of the process (for reading).
+ Return the standard input of the process (for writing).
+ Wait for process termination, return exit code.
+ Return the exit code of the process, will wait for termination.
+ Return true if process still running.
+ Kills (terminates) the process.
Copyright (C) 2010 Miki Tebeka <email@example.com>