Karma upvotes for users/nicks; fixing the delimiters

[prdes]

According to the current setup, when the following nick patterns are upvoted (++),

1. nick++
2. nick ++
3. nick: ++
4. nick, ++

The increment doesn't strip the space char, nor the various other chars that clients seem to have appended to autocompleted nicks as defaults, resulting in every pattern having 1 vote.

[prdes]

#1496
Now this is the concept borrowed from the karma implementation in Bitbot in terms of the regex and the reverse karma (which isn't particularly necessary imo) but the parenthesis version is interesting.

Issue is that it is only using ++ and -- as the inc and dec chars respectively.

P.S. Naturally there are tests to be written

[prdes]

I'll just use %s for the inc and dec variables.