Does not support iConomy 6

[ruifung]

Showcase does not support iconomy 6, upon attempting to buy from a showcase, the following is displayed in console.

19:46:36 [WARNING] No Payment method found! Plugins that rely on this might not work! (And you might see an exception stack trace below this).
19:46:36 [SEVERE] Could not pass event PLAYER_INTERACT to Showcase
java.lang.NullPointerException
at com.narrowtux.showcase.types.RefillAssistant.updateText(RefillAssistant.java:99)
at com.narrowtux.showcase.types.RefillAssistant.(RefillAssistant.java:80)
at com.narrowtux.showcase.types.FiniteShowcaseExtra.onRightClick(FiniteShowcaseExtra.java:88)
at com.narrowtux.showcase.ShowcasePlayerListener.onPlayerInteract(ShowcasePlayerListener.java:43)
at org.bukkit.plugin.java.JavaPluginLoader$11.execute(JavaPluginLoader.java:314)
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:58)
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:338)
at org.bukkit.craftbukkit.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:168)
at net.minecraft.server.ItemInWorldManager.interact(ItemInWorldManager.java:259)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:592)
at net.minecraft.server.Packet15Place.a(SourceFile:57)
at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:92)
at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:464)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:417)