Support for mongodb:// URL scheme

[mschuetz]

Hi Marcello,

I noticed that the connection URL one gets from mongohq/heroku use the URL scheme mongodb:// instead of mongo:// and hence added support for that.

Cheers

Matthias

[marcello3d]

If you use (?:db)? it will be a non-matching group (and you won't have to change all the match numbers). We should update the documentation as well.

I'm also fine with only supporting "mongodb://" if that's the emerging standard, it'd be nice to keep things simple.

(On an unrelated note, it looks like there's a typo in the existing new Error bit... should be + url instead of + arg. I'll fix that.)

[mschuetz]

I reimplemented the whole thing using the builtin URL parser. What do you think about that? 27da610

[marcello3d]

It's clever, but too complicated. Unfortunately it also loses some of functionality of the original, e.g. being able to use just the string "127.0.0.1:27000". It's also not clear how it will handle usernames or passwords with ':' in them.