2ea62cae48 Improve docs about feeler connections (Gleb Naumenko)
Pull request description:
"feeler" and "test-before-evict" are two different strategies suggest in [Eclipse Attacks on Bitcoin’s Peer-to-Peer Network](https://www.usenix.org/system/files/conference/usenixsecurity15/sec15-paper-heilman.pdf). In our codebase, we use `ConnType::FEELER` to implement both.
It is confusing, up to the point that our documentation was just incorrect.
This PR:
- ~clarifies this aspect by renaming "ConnType::FEELER" to "ConnType::PROBE", meaning that this connections only probes that the node is operational, and then disconnects.~
- fixes the documentation
ACKs for top commit:
amitiuttarwar:
ACK 2ea62cae48. thank you!
practicalswift:
ACK 2ea62cae48
Tree-SHA512: c9c03c09eefeacec28ea199cc3f697b0a98723f2f849f7a8115edc43791f8165e296e0e25a82f0b5a4a781a7de38c8954b48bf74c714eba02cdc21f7460673e5