import couchdb-setup

[janl]

In the monorepo merge, it seems I left out moving couchdb-setup over to this repo. This issue is to track the plan and progress of rectifying this oversight.

• merge existing PRs
  • require nodecount on setup couchdb-setup#4
  • Add test suite for http endpoints couchdb-setup#6 | blocked by Add test suite for http endpoints couchdb-setup#6
  • Fixed some minor errors in the documentation. couchdb-setup#10
  • add_node: Don't fail if node name != "couchdb" or "node1" couchdb-setup#11
  • fix cluster setup: use same admin pw salt on all nodes couchdb-setup#12
• import code into this repo as per https://issues.apache.org/jira/browse/COUCHDB-3300