Import errors with dates containing timezones; Import exceptions; Correctly show multiline errors;
Set php.ini ignore_repeated_errors to true
Replace self:: with static::
Caching SQL queries only works with prepare() as query() sends the query directly to the database server. Trigger an error when cached queries are not used with prepare().
Don't cache empty result sets. This can be overridden with the new setCache() $cache_empty parameter.
Force valid cache key names
Stricter check for variable names