Makes the event HUD work

*Finishes up the partially-implemented event HUD (The one the event pref in the VORE character setup tab is for) and adds a verb to let event managers give it to people (can be used by right-clicking them, or from the "Fun" verb tab.
Tested.

code/modules/mob/living/carbon/human/human_helpers.dm

@@ -190,6 +190,10 @@
 	if(nif)
 		compiled_vis |= nif.planes_visible()
 	//VOREStation Add End
+	//VOREStation Add - event hud
+	if(vantag_hud)
+		compiled_vis |= VIS_CH_VANTAG
+	//VOREStation Add End
 
 	if(!compiled_vis.len && !vis_enabled.len)
 		return //Nothin' doin'.

code/modules/mob/mob_helpers_vr.dm

@@ -0,0 +1,14 @@
+/mob/recalculate_vis()
+	. = ..()
+	if(!plane_holder || !vis_enabled)
+		return
+
+	if(vantag_hud)
+		if(!(VIS_CH_VANTAG in vis_enabled))
+			plane_holder.set_vis(VIS_CH_VANTAG,TRUE)
+			vis_enabled += VIS_CH_VANTAG
+	else
+		if(VIS_CH_VANTAG in vis_enabled)
+			plane_holder.set_vis(VIS_CH_VANTAG,FALSE)
+			vis_enabled -= VIS_CH_VANTAG
+	return