Added new permission system

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/permissions/PermissionDefault.java

@@ -0,0 +1,65 @@
+package org.bukkit.permissions;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Represents the possible default values for permissions
+ */
+public enum PermissionDefault {
+    TRUE("true"),
+    FALSE("false"),
+    OP("op", "isop", "operator", "isoperator", "admin", "isadmin"),
+    NOT_OP("!op", "notop", "!operator", "notoperator", "!admin", "notadmin");
+
+    private final String[] names;
+    private final static Map<String, PermissionDefault> lookup = new HashMap<String, PermissionDefault>();
+
+    private PermissionDefault(String... names) {
+        this.names = names;
+    }
+
+    /**
+     * Calculates the value of this PermissionDefault for the given operator value
+     *
+     * @param op If the target is op
+     * @return True if the default should be true, or false
+     */
+    public boolean getValue(boolean op) {
+        switch (this) {
+            case TRUE:
+                return true;
+            case FALSE:
+                return false;
+            case OP:
+                return op;
+            case NOT_OP:
+                return !op;
+            default:
+                return false;
+        }
+    }
+
+    /**
+     * Looks up a PermissionDefault by name
+     *
+     * @param name Name of the default
+     * @return Specified value, or null if not found
+     */
+    public static PermissionDefault getByName(String name) {
+        return lookup.get(name.toLowerCase().replaceAll("[^a-z!]", ""));
+    }
+
+    @Override
+    public String toString() {
+        return names[0];
+    }
+    
+    static {
+        for (PermissionDefault value : values()) {
+            for (String name : value.names) {
+                lookup.put(name, value);
+            }
+        }
+    }
+}