Use randomized, truncated exponential backoff in event of conflict

BugzID: 42053

This is a cherry-pick of:

https://github.com/cloudant/couch_replicator/commit/6e8fbb6a3f2622c14ae605c18ec54cbad7d389f3

Conflicts:
	src/couch_replicator_manager.erl
1 file changed
tree: 77a67a1eef758e97eba9028a0e9138ae728db2b5
  1. priv/
  2. src/
  3. test/
  4. .gitignore