moved streams code around, added stub for DateRollingFileStream

lib/streams/DateRollingFileStream.js

@@ -0,0 +1,16 @@
+var BaseRollingFileStream = require('./BaseRollingFileStream'),
+    util = require('util');
+
+module.exports = DateRollingFileStream;
+
+function DateRollingFileStream(filename, pattern, options) {
+    if (typeof(pattern) === 'object') {
+        options = pattern;
+        pattern = null;
+    }
+    this.pattern = pattern || 'yyyy-mm-dd';
+
+    DateRollingFileStream.super_.call(this, filename, options);
+}
+
+util.inherits(DateRollingFileStream, BaseRollingFileStream);