Use go-ipfs-http-client for request handling

[magik6k]

This code is pretty much the same in both places, this should make the maintenance easier.

Fixes ipfs/go-ipfs-http-client#5, Depends on ipfs/go-ipfs-http-client#18

[Stebalien]

cc @postables. Does this break anything?

[Stebalien]

@magik6k could you test this against tools like ipget? If that still works, I'm fine going ahead with this.

[bonedaddy]

Finally noticed the cc and got around to testing some of the tools I have that use go-ipfs-api. This change breaks some functions of tools I have written that have non-standard ways of using go-ipfs-api.

I don't really see this as an issue, certainly not something worth trying to prevent this PR from being merged simply because:

• It's non standard code that isn't part of upstream (ipfs/go-ipfs-api) which should be expected to break at some point in time because its not officially part of the codebase
• I'm probably the only one, or only one of a few people using these non-standard methods
• The benefits of this PR vastly outweigh any perceived benefits from unofficial code

If desired I can follow this post up with examples of the non-standard functions I'm using. For clarification, all the errors that I'm getting are failed to connect to ipfs node at '<insert-ip-address>': operation not supported

tl;dr

LGTM but it may effect some people using this library in ways that aren't part of ipfs/go-ipfs-api however this is probably a non-issue

[Stebalien]

@postables some examples would definitely be helpful.