new options for jail introduced addfailregex/addignoreregex #867

feature request (#867): new options for jail introduced `addfailregex`/`addignoreregex`: extends regex specified in filter (opposite to `failregex`/`ignoreregex` that overwrites it);

BF: failregex declared direct in jail was joined to single line (specifying of multiple expressions was not possible);

Here I've forgotten it, thanks, commit will follow.
In tests below, it was always `addfailregex`, if convert generates a stream for the server.