column, butcher and ammo tweaks

- ammo in equipment/item columns is now grouped by type/material/quality
- all grid columns now correctly accept different background colors
- role cells with active labors will use a gradient depending on how
many of the associated labors are active
- non-butcherable creatures can't be butchered
- fixed the cell coloring/shading on some types of cells where it would
color outside of the cell
- squad names are shown in the optimizer log (was bugged)
- updated role calculations to use another new method to reduce the
severity when many low values are paired with high values (skills)