Add nLocalServices info to RPC getinfo

Also show full 64 bits of services. Previously service bits >32 that
were advertised just didn't show up at all.
Add comment regarding experimental-use service bits

As per mailing list discussion.
Merge pull request #4380

38405ac Add comment regarding experimental-use service bits (Peter Todd)
99ddc6c Add nLocalServices info to RPC getinfo (Peter Todd)