Tidy up hints, small issues.

docs/issues.txt

@@ -11,10 +11,6 @@ ISSUES: Bugs, Cleanup and Refinements
 
 - falling_node pillars settle out of order!
 
-- Make sure sponges can soak up artificial water too (test empirically).
-
-- Prism-making hint only works on off prism, needs to work with on+gated.
-
 - Add hint for recycling glass(es) to sand?
 
 - Delayed hint witnessing?
@@ -23,14 +19,9 @@ ISSUES: Bugs, Cleanup and Refinements
 	- Use for witnessing fermentation recipes like peat/humus,
 	  humus/dirt, dirt/sand.
 
-- Sprinting up a ladder is possible.  Should it be?
-
 - Tote recycling is possible but has no hint.
 	- Should recipe be changed?  Heat it back into a cube if empty?
 
-- Coal chopping recipe should give credit upon chopping any
-  non-fully-ash charcoal, not just on picking up lump.
-
 - Tree soil rate should bias closer nodes to have higher impact...?
 
 - Should tree growth rate start out faster but slow down?

mods/nc_guide/hints.lua

@@ -151,7 +151,17 @@ addhint("find charcoal",
 )
 
 addhint("chop up charcoal",
-	"nc_fire:lump_coal",
+	{true,
+		"nc_fire:lump_coal",
+		"chop nc_fire:coal1",
+		"chop nc_fire:coal2",
+		"chop nc_fire:coal3",
+		"chop nc_fire:coal4",
+		"chop nc_fire:coal5",
+		"chop nc_fire:coal6",
+		"chop nc_fire:coal7",
+		"chop nc_fire:coal8"
+	},
 	"group:charcoal"
 )
 
@@ -506,30 +516,33 @@ addhint("cool molten glass into crude glass",
 )
 
 addhint("chip chromatic glass into prisms",
-	"nc_optics:prism",
+	"group:silica_prism",
 	"nc_optics:glass_opaque"
 )
 
 addhint("chop chromatic glass into lenses",
-	"nc_optics:lens",
+	"group:silica_lens",
 	"nc_optics:glass_opaque"
 )
 
-local opticactive = {true, "nc_optics:lens_on", "nc_optics:prism_on"}
-
 addhint("activate a lens",
-	opticactive,
-	"nc_optics:lens"
+	"nc_optics:lens_on",
+	"group:silica_lens"
 )
 
 addhint("produce light from a lens",
 	"nc_optics:lens_glow",
-	opticactive
+	"group:silica_lens"
+)
+
+addhint("activate a prism",
+	"nc_optics:prism_on",
+	"nc_optics:lens_on"
 )
 
 addhint("gate a prism",
 	"nc_optics:prism_gated",
-	opticactive
+	"nc_optics:lens_on"
 )
 
 addhint("assemble a glass tank",

mods/nc_optics/prism.lua

@@ -40,7 +40,8 @@ local basedef = {
 	groups = {
 		silica = 1,
 		optic_check = 1,
-		cracky = 3
+		cracky = 3,
+		silica_prism = 1
 	},
 	drop = modname .. ":prism",
 	on_construct = nodecore.optic_check,