API Overhaul

[Stebalien]

• [x] #8 Extract DAGService and friends
  • [x] Get a review on the last few commits
  • [x] Get a final sign off.
  • [x] Merge it!
• [ ] Fix all the other IPLD Node API issues all at once (annother PR)
  • [ ] #9 Remove the Link structure, it's DagProtobuf specific
  • [ ] #12 Remove the Size method
  • [ ] #10 Remove the Copy method
  • [ ] #11 Remove the Stat method
  • [ ] #24 Merge the resolver interface into the Node interface.
• [ ] Update all other IPLD implementations to use the now fixed IPLD Node API.
• [ ] Update go-ipfs all at once.
  • [ ] Fix ProtoNode to actually be a proper IPLD node and introduce a new FSNode interface for IPFS specific stuff.

I originally planned on doing this in stages but I'm now of the opinion that breaking everything all at once will be much less painful (it will still be very painful...).

[Stebalien]

cc @kevina, @whyrusleeping, @Kubuxu

[kevina]

@Stebalien I don't have any problems the idea but I would need to see more of the implementation before I can provide any useful feedback.

[warpfork]

I just clicked a bunch of checkmarks in here because it to me like some of the referenced issues have been merged :)

[Stebalien]

Yeah, just not the other ones "like making dag nodes behave".