change to single MIT license. update banners in source files

src/common/print.css

@@ -1,14 +1,13 @@
-/*
+/*!
  * <%= meta.title %> v<%= meta.version %> Print Stylesheet
- *
+ * Docs & License: <%= meta.homepage %>
+ * (c) <%= meta.copyright %>
+ */
+
+/*
  * Include this stylesheet on your page to get a more printer-friendly calendar.
  * When including this stylesheet, use the media='print' attribute of the <link> tag.
  * Make sure to include this stylesheet IN ADDITION to the regular fullcalendar.css.
- *
- * (c) <%= meta.copyright %>
- * Dual licensed under the MIT and GPL licenses, located in
- * MIT-LICENSE.txt and GPL-LICENSE.txt respectively.
- *
  */