Feature: allow for a channel-wide tally that people can add/subtract from (for #lost-hours)

[klundberg]

People in #lost-hours often update the count in the channel topic whenever they're adding hours they spent that were wasted on something. It'd be nice to just say something like

@camille hours += 2.5

or something along those lines (the less typing required the better), so that camille could keep track of hours lost. It might not even need any serverside tracking if camille could just read the current total from the topic, make the numeric change and write the new topic back.

[ghost]

As the creator of #lost-hours, I fully endorse this idea!