concat-v1.5

Release notes:

• Mediachain identity [PR #110] [PR #112] [PR #118]
• Node manifests [PR #116]
• Improved IPFS interopability [PR #113]
• Misc fixes and improvements
  • Deduplicate wkis in compound statements [PR #107] [PR #108]
  • Parallelize directory and DHT lookups, with more reasonable timeouts [PR #109]
  • Canonical JSON marshalling for statements in query results [PR #111]