Remove default parameter value of is_php()

It was simply pointless.

Author: vlakoff

system/core/Common.php

@@ -51,14 +51,14 @@
 	 * @param	string
 	 * @return	bool	TRUE if the current version is $version or higher
 	 */
-	function is_php($version = '5.3.0')
+	function is_php($version)
 	{
 		static $_is_php;
 		$version = (string) $version;
 
 		if ( ! isset($_is_php[$version]))
 		{
-			$_is_php[$version] = (version_compare(PHP_VERSION, $version) >= 0);
+			$_is_php[$version] = version_compare(PHP_VERSION, $version, '>=');
 		}
 
 		return $_is_php[$version];

user_guide_src/source/changelog.rst

@@ -480,6 +480,7 @@ Release Date: Not Released
       -  Added function :func:`function_usable()` to work around a bug in `Suhosin <http://www.hardened-php.net/suhosin/>`.
       -  Removed the third (`$php_error`) argument from function :func:`log_message()`.
       -  Changed internal function ``load_class()`` to accept a constructor parameter instead of (previously unused) class name prefix.
+      -  Removed default parameter value of :func:`is_php()`.
 
    -  :doc:`Output Library <libraries/output>` changes include:
 

user_guide_src/source/general/common_functions.rst

@@ -13,13 +13,13 @@ loading any libraries or helpers.
 
   <div class="custom-index container"></div>
 
-.. function:: is_php([$version = '5.3.0'])
+.. function:: is_php($version)
 
 	:param	string	$version: Version number
 	:returns:	TRUE if the running PHP version is at least the one specified or FALSE if not
 	:rtype:	bool
 
-	Determines of the PHP version being used is greater than the
+	Determines if the PHP version being used is greater than the
 	supplied version number.
 
 	Example::