put file logs in log directory by default, changelog update

CHANGELOG.md

@@ -4,3 +4,4 @@
 * stdin is saved as a file in dl/ when using exec commands 
     to support commands like 'cat >file; ./file'
 * allow wget download over non-80 port
+* simple JSON logging to kippo.json

kippo.cfg.dist

@@ -209,9 +209,9 @@ interact_port = 5123
 # [database_textlog] line.
 
 #[database_textlog]
-#logfile = kippo-textlog.log
+#logfile = log/kippo-textlog.log
 
 # JSON based logging module
 
 #[database_jsonlog]
-#logfile = kippolog.json
+#logfile = log/kippolog.json