Output granularity ruleset setting
For a long time I've been wanting to setup rules (either a new ruleset or modifying existing one) with much finer granularity of outputs than freeciv currently allows. To use one potential new ruleset as an example, ctp2 has buildings that reduce corruption just 10%. Such a building makes no sense in current freeciv as the benefit from it would always be 0, and yet the minimum positive upkeep cost we could assign to it would be 1.
For most part increasing the output values should be doable with our ruleset formats, but client display of tile outputs has kept me from even trying. There the sensible output values are single digit, 0-9.
The patch I'm about to attach here tries to address this to some extend, though it's still far from perfect solution. It introduces ruleset value civstyle.output_granularity. For all existing rulesets its value is 1, and typically one wants value always to be 10^n. At first the only use for this value is for the client to scale which output sprites it uses. If the output_granularity value is 10, sprite shown by the client tells tens of output points.