Fix integer overflow in calender.

Fix int overflows in conversation functions for calendar.
Add tests for the overflows.

Author: Joshua Rogers

ext/calendar/calendar.c

@@ -12,7 +12,7 @@
    | obtain it through the world-wide-web, please send a note to          |
    | license@php.net so we can mail you a copy immediately.               |
    +----------------------------------------------------------------------+
-   | Authors: Shane Caraveo             <shane@caraveo.com>               | 
+   | Authors: Shane Caraveo             <shane@caraveo.com>               |
    |          Colin Viebrock            <colin@easydns.com>               |
    |          Hartmut Holzgraefe        <hholzgra@php.net>                |
    |          Wez Furlong               <wez@thebrainroom.com>            |

ext/calendar/gregor.c

@@ -195,7 +195,7 @@ zend_long GregorianToSdn(
 						   int inputMonth,
 						   int inputDay)
 {
-	int year;
+	zend_long year;
 	int month;
 
 	/* check for invalid dates */

ext/calendar/julian.c

@@ -217,7 +217,7 @@ zend_long JulianToSdn(
 						int inputMonth,
 						int inputDay)
 {
-	int year;
+	zend_long year;
 	int month;
 
 	/* check for invalid dates */

ext/calendar/tests/gregoriantojd_overflow.phpt

@@ -0,0 +1,10 @@
+--TEST--
+gregoriantojd()
+--SKIPIF--
+<?php include 'skipif.inc'; ?>
+--FILE--
+<?php
+echo gregoriantojd(5, 5, 6000000) . "\n";
+?>
+--EXPECT--
+2193176185

ext/calendar/tests/juliantojd_overflow.phpt

@@ -0,0 +1,10 @@
+--TEST--
+juliantojd()
+--SKIPIF--
+<?php include 'skipif.inc'; ?>
+--FILE--
+<?php
+echo juliantojd(5, 5, 6000000000) . "\n";
+?>
+--EXPECT--
+622764916319