Add support for element ID generation

[Gozala]

Github generates id's for each h1 element, which is super useful for sharing links. It would be great if marked allow id generation for each token lexer creates. I think it would be best if there was marked.serializethat takes output of marked.lexer and also recognized id and className attributes.

[claudioc]

Subscribing!

[leeola]

wow, had no idea that this was such a widely accepted issue. There are a dozen people coming up with different ways to solve this :/.

Is this the central place to discuss this issue? And if so, what is the most stable feature branch for this? I'm looking to fork someone to get this feature in asap. I was making my own, based on #119 but it appears everyone seems to be doing that..

So yea, i should probably not add to the pile.

[joshbruce]

Seems resolved. Closing.