Moved WEPIF to the com.sk89q.wepif package and made PermissionsResolverManager a singleton

Added OfflinePlayer permissions fetching methods to WEPIF

src/main/java/com/sk89q/wepif/WEPIFRutimeException.java

@@ -0,0 +1,12 @@
+package com.sk89q.wepif;
+
+/**
+ * @author zml2008
+ */
+public class WEPIFRutimeException extends RuntimeException {
+    
+    public WEPIFRutimeException(String message) {
+        super(message);
+    }
+
+}