Workaround for #661: this makes the `CAP LS 302` line from the default config
fit on a single line, as long as the server name is at most 35 characters.

tor-listeners.listeners was checked against listen,
but listen is obsolete now, so config load would fail
on a config that used the new style `listeners` instead of
`listen` --- unless tor-listeners.listeners was empty, which
it should be under the new style, but there's no need to enforce
that

1. DRY "banner" descriptions of each services
2. `/HELP NICKSERV` now refers the user to `/NICKSERV HELP`, etc.
3. Fix double translation of `textGenerator` output

1. Your own snomasks would be reported as belonging to the other user
2. Prefixes were incorrect

dan: "I probably wouldn't expect those mappings to cause much
trouble at all for legitimate users at the end of the day"

shivaram: [concurs]

'm' skeletonizes to 'rn' (but is exempted by the isBoring check),
but the fullwidth 'ｍ' does not skeletonize to anything. The root cause
of this is the (still unexplained) patchiness of the skeleton mapping
for fullwidth -> standard-width Latin characters; the fix is to perform
width mapping first, before either skeletonization or isBoring.

Partially fixed earlier in #467