Improve workflow handling of plant reactions

Makes workflow understand "seeds of any plant", "thread of any plant",
"drink of any plant", "powder of any plant", and "liquid of any plant"
when counting items.

Changes workflow's handling of the built-in plant reactions to
understand that they always produce plant products, and that they also
produce seeds.

This means that you can set a target for, for example, "powder of any
plant", and workflow will use a milling job to produce that.

library/modules/Materials.cpp

@@ -396,6 +396,11 @@ bool MaterialInfo::matches(const df::job_material_category &cat)
 
     using namespace df::enums::material_flags;
     TEST(plant, STRUCTURAL_PLANT_MAT);
+    TEST(plant, SEED_MAT);
+    TEST(plant, THREAD_PLANT);
+    TEST(plant, ALCOHOL_PLANT);
+	TEST(plant, POWDER_MISC_PLANT);
+	TEST(plant, LIQUID_MISC_PLANT);
     TEST(wood, WOOD);
     TEST(cloth, THREAD_PLANT);
     TEST(silk, SILK);

plugins/lua/workflow.lua

@@ -203,12 +203,20 @@ for job,flag in pairs(plant_products) do
     local itag = 'idx_'..string.lower(flag)
     job_outputs[job] = function(callback, job)
         local mat_type, mat_index = -1, -1
+		local seed_type, seed_index = -1, -1
         local mat = dfhack.matinfo.decode(job.job_items[0])
         if mat and mat.plant and mat.plant.flags[flag] then
             mat_type = mat.plant.material_defs[ttag]
             mat_index = mat.plant.material_defs[itag]
+			seed_type = mat.plant.material_defs['type_seed']
+			seed_index = mat.plant.material_defs['idx_seed']
         end
-        default_output(callback, job, mat_type, mat_index)
+		local mat_mask = { }
+		if flag ~= 'LEAVES' then
+			mat_mask.plant = true
+		end
+	    default_output(callback, job, mat_type, mat_index, mat_mask)
+		callback{ item_type = df.item_type.SEEDS, mat_type = seed_type, mat_index = seed_index }
     end
 end