List canonical abbreviations to use in Tor functions and identifiers
We often don't abbreviate things in our function names and global identifiers. This leads to beautiful things like "router_get_mutable_consensus_status_by_descriptor_digest" and "signed_descs_update_status_from_consensus_networkstatus" and "networkstatus_consensus_can_use_multiple_directories".
What's more, when we do abbreviate, we often do so inconsistently: cfg versus config, con vs conn, orconn vs or_conn, and so on.
We should specify which abbreviations we want to standardize, and converge on those.
It is most important to do this for identifiers that are visible across modules, followed by identifiers that are global within a module. I don't think we need to do this for local variables.