Replace all modular HTML spans with defines spans

In total:
- Adds span defines for `reallybig hypnophrase`, `big warning`, `header`
- Fixes a missing apostrophe for hypno stare
- Makes a special exception for cuddling.dm, which uses an irregular span
- Puts the spans file back

modular_splurt/code/modules/smithing/anvil.dm

@@ -11,4 +11,4 @@
 	if(isdwarf(user))
 		return ..()
 	else
-		to_chat(user, "<span class='warning'>Ugh! This anvil smells of mushroom beer, and the design is weird. It is inconvenient to use it!</span>")
+		to_chat(user, span_warning("Ugh! This anvil smells of mushroom beer, and the design is weird. It is inconvenient to use it!"))