added function "int levdist(string str1, string str2)"

that will calculate the Levenshtein distance between two
strings (faster and possibly more accurate than similar_text())

ext/standard/basic_functions.c

@@ -162,6 +162,7 @@ function_entry basic_functions[] = {
 	PHP_FE(implode,									NULL)
 	PHP_FE(setlocale,								NULL)
 	PHP_FE(soundex,									NULL)
+	PHP_FE(levdist,									NULL)
 	PHP_FE(chr,										NULL)
 	PHP_FE(ord,										NULL)
 	PHP_FE(parse_str,								NULL)