Fix undefined error when custom strict fields don't exist in a turba driver
Do not force the database when one is explicitly specified.

It is EXTREMELY dangerous to do this. E.g.,

$client = new Horde_Mongo_Client();

// This inserts into 'horde' even though you specify 'test_database'.
$client->test_database->my_collection->insert($document);

// This completely nukes your 'horde' database.
$client->test_database->drop();
Don't need to override this anymore.
Avoid E_STRICT warnings.
Return the currently selected database by default.
phpdoc

InvalidArgumentException doesn't need to be documented; this is a logic
error (as opposed to runtime error).
[mms] getAvatarUrl() now returns a Horde_Url object.
[mms] Change second parameter to getAvatarUrl() and fetchAvatar() to an array so that additional options can be provided.
[mms] Add 'default' and 'rating' options to getAvatarUrl().
Merge branch 'master' into imp_6_2