overlib MDL-19735 Overlib is now included only where it is used

At the same time I have converted the calendar block to use YUI instead of overlib, this introduces one regression in that the panel is shown immediatly but should really have a minimal delay for usability.
This will be fixed once the theme changes for 2.0 have been commited

calendar/view.php

@@ -133,6 +133,8 @@
     $strcalendar = get_string('calendar', 'calendar');
     $prefsbutton = calendar_preferences_button();
 
+    $PAGE->requires->js('calendar/calendar.js');
+
     // Print title and header
     $PAGE->set_title("$site->shortname: $strcalendar: $pagetitle");
     $PAGE->set_heading($strcalendar);
@@ -141,8 +143,6 @@
 
     echo $OUTPUT->header();
 
-    echo calendar_overlib_html();
-
     // Layout the whole page as three big columns.
     echo '<table id="calendar" style="height:100%;">';
     echo '<tr>';