Cleanup

- Mark PathBasedRepositoryLocationResolver as singleton so that other
  users will get the same instance and will not overwrite the paths
  set by migration.
- Set path kept by InlineMigrationStrategy in location resolver to
  store the path.
- Add logging
- Add type of repository to migration web page

scm-webapp/src/main/java/sonia/scm/update/MigrationWizardModule.java

@@ -1,14 +1,20 @@
 package sonia.scm.update;
 
 import com.google.inject.servlet.ServletModule;
-import sonia.scm.update.repository.XmlRepositoryV1UpdateStep;
-
-import java.util.List;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class MigrationWizardModule extends ServletModule {
 
+  private static final Logger LOG = LoggerFactory.getLogger(MigrationWizardModule.class);
+
   @Override
   protected void configureServlets() {
+    LOG.info("==========================================================");
+    LOG.info("=                                                        =");
+    LOG.info("=             STARTING MIGRATION SERVLET                 =");
+    LOG.info("=                                                        =");
+    LOG.info("==========================================================");
     serve("/*").with(MigrationWizardServlet.class);
   }
 }