Cleaned up unterminated brackets in dictionary.

Coincidentally found broken source reference in 'cite:' field of {tlhuH}
[1.2] (page number and trailing bracket was missing). Therefore improved
`bin/check-dict` to check for paired punctuation (i.e. various brackets +
"..." and ~...~).

Also made the changes necessary to `dict.zdb` to make it pass all the
checks.