PDO debug_info handler

Hey,

I noticed PDO has no debug_info handler.

This is always asked by developpers to have informations about
internal state while var_dump()ing objects as calling getAttribute()
can be weird sometimes when you need all info at once.
Note that PDOStatement has a (light) handler.

I started an implementation, here :
https://github.com/jpauli/php-src/tree/pdo_debug_info

The hardest part is missing, aka, retrieving driver specific informations.
I'll do this soon.

Thoughts ?
Johannes, perhaps you 've been asked in past about such a feature ?

I added some driver info.
Can't go further safely without redesigning the API.

Julien Pauli