[WIP] gx: update go-merkledag to match version used in go-unixfs

[schomatis]

Do not merge.

See ipfs/go-unixfs#4.

[schomatis]

Closed due to forced push.

[whyrusleeping]

You'll also need to update go-blockservice I think. Run gx deps dupes to see if anything looks wrong.

[schomatis]

gx deps dupes reported (among many duplicates) the old hash of go-merkledag being used, I grep'ed for it in the gx dir (is there an easier way for this? a gx flag to know which package is importing the old hash?) and it seems that the go-path version used in go-ipfs is using it, although this doesn't affect the build (probably because those two don't interact), should I update the go-path version in this same PR?

[schomatis]

So, this is breaking the build because I updated go-merkledag to the version used by the master branch of go-unixfs (for gx-go link to work) but go-ipfs is using a gx-version of go-unixfs which is actually using the old go-merkledag version (QmRy4Q...s59) that I'm updating here, so I guess I need to first update go-unixfs here to the master version gx-release (that uses the new go-merkledag version QmfGzd...9TS) and then update go-merkledag, or maybe that needs to happen in the same PR otherwise I think there might be a version mismatch in the converse relation of the what's happening here now that's breaking the build (my head is aching at this point so I'm going to take a pause here and rethink this, let's not merge anything until then).

[schomatis]

Closing in favor of #5336, thanks @hsanjuan!