Fix the EXDATE parameter

- Per @takkaria 's suggestion, actually pay attention to the
  spec and put the EXDATE parameter as it's own line.
- Also use a colon instead of an equal sign (since it is it's
  own property)

TODO: Write the test case(s) for this.

lib/event.js

@@ -702,14 +702,17 @@ var ICalEvent = function(_data, calendar) {
                 g += ';BYMONTHDAY=' + data.repeating.byMonthDay.join(',');
             }
 
-            if(data.repeating.exclude) {
-                g += ';EXDATE=';
-                var sArr = [];
-                data.repeating.exclude.forEach(function(excludedDate) {
-                    sArr.push(tools.formatDate(excludedDate));
-                });
-                g += sArr.join(',');
-            }
+            g += '\r\n';
+        }
+
+        // REPEATING EXCLUSION
+        if(data.repeating.exclude) {
+            g += 'EXDATE:';
+            var sArr = [];
+            data.repeating.exclude.forEach(function(excludedDate) {
+                sArr.push(tools.formatDate(excludedDate));
+            });
+            g += sArr.join(',');
 
             g += '\r\n';
         }