Add cancellable FactionRelationWishEvent

This event is called before a faction relation wish is applied by a
player using `/f relation`

src/main/java/com/massivecraft/factions/event/FactionRelationWishEvent.java

@@ -0,0 +1,44 @@
+package com.massivecraft.factions.event;
+
+import com.massivecraft.factions.FPlayer;
+import com.massivecraft.factions.Faction;
+import com.massivecraft.factions.struct.Relation;
+import org.bukkit.event.Cancellable;
+
+public class FactionRelationWishEvent extends FactionPlayerEvent implements Cancellable {
+    private final Faction targetFaction;
+    private final Relation currentRelation;
+    private final Relation targetRelation;
+
+    private boolean cancelled;
+
+    public FactionRelationWishEvent(FPlayer caller, Faction sender, Faction targetFaction, Relation currentRelation, Relation targetRelation) {
+        super(sender, caller);
+
+        this.targetFaction = targetFaction;
+        this.currentRelation = currentRelation;
+        this.targetRelation = targetRelation;
+    }
+
+    public Faction getTargetFaction() {
+        return targetFaction;
+    }
+
+    public Relation getCurrentRelation() {
+        return currentRelation;
+    }
+
+    public Relation getTargetRelation() {
+        return targetRelation;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    @Override
+    public void setCancelled(boolean cancelled) {
+        this.cancelled = cancelled;
+    }
+}