ssh: turn off entry merging for known_hosts
Revert "ssh: turn off entry merging for known_hosts"

On the second thought, this makes it easier to spot identical keys...

This reverts commit 0e6099387bcac44b8e69404ca9c583d5ddfab1e8.
ssh: hosts (theos = git)
ssh/config: use 'local' hosts file for 10.0.0.0/8