Each download of node's `index.tab` now merges every version's LTS codename, or `-`, into `$NVM_DIR/.lts-status`,
keeping versions that download doesn't list,
so the status of an installed version is known, and refreshed on every remote connection.
Only an index that includes LTS versions can start the record, so a nightly or release candidate mirror can't,
and `nvm_ensure_lts_status` downloads it once for versions installed before it was recorded.
`update_test_mocks.sh` writes the record of its `index.tab` mock to `nodejs.org-dist-lts-status.txt`.
Jordan Harband
e5f1288b40