Add setAuthorizer method to SQLite3

This adds the possibility to define a userland callback that will be
used to authorize or not an action on the database.

ext/sqlite3/php_sqlite3_structs.h

@@ -71,6 +71,8 @@ typedef struct _php_sqlite3_db_object  {
 	sqlite3 *db;
 	php_sqlite3_func *funcs;
 	php_sqlite3_collation *collations;
+	zend_fcall_info authorizer_fci;
+	zend_fcall_info_cache authorizer_fcc;
 
 	zend_bool exception;