Implement the stream flag for pin ls

[Stebalien]

Once go-ipfs 0.5.0 has been released.

[aschmahmann]

The streaming interface has been implemented, but we're still not streaming the results over HTTP.

[godcong]

The streaming interface has been implemented, but we're still not streaming the results over HTTP.

Do we still need to retain non-stream state queries.
If you want to achieve two states, you need to change
https://github.com/ipfs/interface-go-ipfs-core/blob/b935dfe5375eac7ea3c65b14b3f9a0242861d0b3/options/pin.go#L11

If not needed
I can pr my code now, :)