Improve LDAP support (geoserver#82).

Externalize DB/LDAP selection.
Add caching to LDAP queries.
Downgrade log4j version to 1.x (align to GeoServer)
Upgrade spring-ldap version to 2.x (align to Spring 4 core)
Upgrade geoserver-manager to 1.6.
Clean up obsolete pre-3.0 methods (user and groups refs by id)
Clean up configuration files (geoserver#16)
Remove some dead code in GWT client.
Improve users and groups loading in GWT client.
Clean up misplaced log4j.properties files.
Authorization request filters now can only specify either the user or the group.

.gitignore

@@ -4,3 +4,16 @@
 target
 *iml
 *idea
+
+src/gui/core/plugin/mapsui/war/
+src/gui/core/plugin/userui/war/
+
+src/gui/web/war/WEB-INF/classes/
+src/gui/web/war/WEB-INF/deploy/
+src/gui/web/war/WEB-INF/spatial-lib/
+src/gui/web/war/geofence/
+
+**/gwt-unitCache/
+**/geofence_db/
+**/nbproject/
+

src/gui/core/plugin/mapsui/pom.xml

@@ -1,11 +1,9 @@
 <?xml version="1.0"?>
 <!--
-/* (c) 2014-2016 Open Source Geospatial Foundation - all rights reserved
+/* (c) 2014 - 2017 Open Source Geospatial Foundation - all rights reserved
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-
-
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
@@ -26,15 +24,6 @@
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 	</properties>
 
-	<!--
-		<pluginRepositories> <pluginRepository> <id>gwt-maven</id>
-		<url>http://gwt-maven.googlecode.com/svn/trunk/mavenrepo</url>
-		</pluginRepository> </pluginRepositories> <repositories> <repository>
-		<id>gwt-maven</id> <url>
-		http://gwt-maven.googlecode.com/svn/trunk/mavenrepo/ </url>
-		</repository> </repositories>
-	-->
-
 
 	<dependencies>
 
@@ -156,8 +145,8 @@
 		</dependency>
 
         <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-api</artifactId>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
         </dependency>
 
 		<dependency>