Add initial audit log API

Introduce audit log API which logs all creations,
modifications and deletions of annotated entities
and everything which is stored inside a
ConfigurationStore. Without the related Audit
Log Plugin installed this API does nothing.

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/HgConfig.java

@@ -25,10 +25,12 @@
 package sonia.scm.repository;
 
 import lombok.Value;
+import sonia.scm.auditlog.AuditEntry;
 
 import java.io.File;
 
 @Value
+@AuditEntry(labels = {"hg", "config"})
 public class HgConfig {
 
   String hgBinary;

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/HgGlobalConfig.java

@@ -25,6 +25,7 @@
 package sonia.scm.repository;
 
 
+import sonia.scm.auditlog.AuditEntry;
 import sonia.scm.util.Util;
 
 import javax.xml.bind.annotation.XmlRootElement;
@@ -36,6 +37,7 @@ import javax.xml.bind.annotation.XmlTransient;
  * @author Sebastian Sdorra
  */
 @XmlRootElement(name = "config")
+@AuditEntry(labels = {"hg", "config"})
 public class HgGlobalConfig extends RepositoryConfig {
 
   public static final String PERMISSION = "hg";

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/HgRepositoryConfig.java

@@ -25,11 +25,13 @@
 package sonia.scm.repository;
 
 import lombok.Data;
+import sonia.scm.auditlog.AuditEntry;
 
 import javax.xml.bind.annotation.XmlRootElement;
 
 @Data
 @XmlRootElement
+@AuditEntry(labels = {"hg", "config"})
 public class HgRepositoryConfig {
   String encoding;
 }