PHP Library - Fix for undefined symbol error ZVAL_ADDREF

An undefined symbol error [1] is encountered when attempting to use the PHP jlog library with PHP 5.3. It appears ZVAL_ADDREF was replaced with Z_ADDREF_P per this PHP-Internals discussion [2]. Replacing the ZVAL_ADDREF calls with Z_ADDREF_P addresses this issue for me on PHP 5.3, allowing me to read the jlog.

[1]  jlog.so: undefined symbol: ZVAL_ADDREF.

[2] http://grokbase.com/t/php/php-internals/0794vpam1g/patch-for-macros-for-tracking-refcount-and-is-ref