broctl test suite improvements

Description

Branch "topic/dnthayer/improve-tests" contains the following changes:
1) Fix test serialization (some tests don't need it anymore, and add comments explaining this)
2) Simplify the test setup files (there are too many variations of node.cfg and broctl.cfg)
3) Fix tests that listen for connections to listen on IPv4 loopback
4) Add some new test cases
5) Update docs about "update" cmd being deprecated

Environment

None

Status

Assignee

Jon Siwek

Reporter

Daniel Thayer

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Components

Fix versions

Priority

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