Add autoenv, automatic environment setup

Using a hook, automatically detect when `.enter` and `.exit` scripts
and source them when changing the shells current directory.

autoenv/autoenv.plugin.zsh

@@ -34,7 +34,7 @@ _autoenv_authorized() {
     esac
   done
   # Store authorized associative array in authorized file.
-  echo ${(kv)authorized} > $authorized_file
+  echo ${(kv)authorized) > $authorized_file
 }
 
 # Source an enter script and add its directory to the global entered