Switch to libp2p master

[tomaka]

The current Substrate code uses a fork of libp2p. Now that the changes from this fork have been merged into libp2p master, let's switch to this master branch.

[tomaka]

Note that I didn't test this PR on the live network, since #900 broke the networking.
I think this should be tested (as much as possible right now, which means let it run for a few hours and look if nothing breaks) before being merged.

[pepyakin]

I think the test got [dead]locked and has been running for 374 minutes 26 seconds, so I cancelled it.

[ddorgan]

Just seems to keep hanging on this process node_service, taking all available cpu power:

top - 02:39:05 up 8 days,  9:06,  3 users,  load average: 53.59, 62.43, 66.03
Tasks: 575 total,   1 running, 321 sleeping,   0 stopped,   0 zombie
%Cpu(s):100.0 us,  0.0 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 13189148+total, 61477288 free,  2467352 used, 67946848 buff/cache
KiB Swap:  4190204 total,  4190204 free,        0 used. 12753018+avail Mem 

   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                            
100654 root      20   0  937876 117204  14924 S  4793  0.1 351:41.29 node_service-31       

[bkchr]

What is missing to merge this pull request? Do you had any chance to test it @tomaka?
I really would like to have this merged, to get finally rid of openssl 0.9.x

[tomaka]

@bkchr I've opened #1062. Once merged and determined to run ok (which means running it for 24 hours without any issue), we can confidently merge this one I guess.

[tomaka]

#1062 successfully synced on my machine over night.

[bkchr]

@tomaka so we are good to go and we can merge this? Or do we need more testing?

[tomaka]

Should be good in my opinion.