Slice the list of all events to honor config.maximumEntries

Scenario:
* Specify more than one calendar in `config.calendars`
* Specify a maximum number of entries in `config.maximumEntries`

Result:
The module will show as many as maximumEntries for EACH calendar

Expected:
The module shall not show more than a total of maximumEntries, regardless of how many calendars I specify

Fixes #1043

modules/default/calendar/calendar.js

@@ -356,7 +356,7 @@ Module.register("calendar", {
 			return a.startDate - b.startDate;
 		});
 
-		return events;
+		return events.slice(0, this.config.maximumEntries);
 	},
 
 	/* createEventList(url)