Allow clearing audit events through admin console, and added timer to clear expired events

timer/api/src/main/java/org/keycloak/timer/TimerProvider.java

@@ -0,0 +1,12 @@
+package org.keycloak.timer;
+
+import org.keycloak.provider.Provider;
+
+/**
+ * @author <a href="mailto:sthorger@redhat.com">Stian Thorgersen</a>
+ */
+public interface TimerProvider extends Provider {
+
+    public void schedule(Runnable runnable, String config);
+
+}

timer/api/src/main/java/org/keycloak/timer/TimerProviderFactory.java

@@ -0,0 +1,9 @@
+package org.keycloak.timer;
+
+import org.keycloak.provider.ProviderFactory;
+
+/**
+ * @author <a href="mailto:sthorger@redhat.com">Stian Thorgersen</a>
+ */
+public interface TimerProviderFactory extends ProviderFactory<TimerProvider> {
+}