Readds borers (#1999)

Readds the cortical borers and also syndi-borers.
Syndi-borers now gives a response if you try to use it multiple times
too quickly, and also prevents usage more than once while it's still
waiting for ghost responses.

code/__DEFINES/is_helpers.dm

@@ -76,6 +76,8 @@
 
 #define isrevenant(A) (istype(A, /mob/living/simple_animal/revenant))
 
+#define isborer(A) (istype(A, /mob/living/simple_animal/borer))
+
 #define isbot(A) (istype(A, /mob/living/simple_animal/bot))
 
 #define iscrab(A) (istype(A, /mob/living/simple_animal/crab))

code/__DEFINES/role_preferences.dm

@@ -23,6 +23,7 @@
 #define ROLE_REVENANT			"revenant"
 #define ROLE_DEVIL				"devil"
 #define ROLE_SERVANT_OF_RATVAR	"servant of Ratvar"
+#define ROLE_BORER				"borer"
 
 //Missing assignment means it's not a gamemode specific role, IT'S NOT A BUG OR ERROR.
 //The gamemode specific ones are just so the gamemodes can query whether a player is old enough
@@ -44,6 +45,7 @@ GLOBAL_LIST_INIT(special_roles, list(
 	ROLE_REVENANT,
 	ROLE_ABDUCTOR = /datum/game_mode/abduction,
 	ROLE_DEVIL = /datum/game_mode/devil,
+	ROLE_BORER,
 	ROLE_SERVANT_OF_RATVAR = /datum/game_mode/clockwork_cult
 ))