SS 4.0 - Upgrade Solr services and stores

code/solr/services/Solr3Service.php

@@ -3,5 +3,5 @@ namespace SilverStripe\FullTextSearch\Solr\Services;
 
 class Solr3Service extends SolrService
 {
-    private static $core_class = 'Solr3Service_Core';
+    private static $core_class = 'SilverStripe\FullTextSearch\Solr\Services\Solr3Service_Core';
 }

code/solr/services/Solr4Service.php

@@ -3,5 +3,5 @@ namespace SilverStripe\FullTextSearch\Solr\Services;
 
 class Solr4Service extends SolrService
 {
-    private static $core_class = 'Solr4Service_Core';
+    private static $core_class = 'SilverStripe\FullTextSearch\Solr\Services\Solr4Service_Core';
 }

code/solr/services/SolrService.php

@@ -10,7 +10,7 @@ Solr::include_client_api();
  */
 class SolrService extends SolrService_Core
 {
-    private static $core_class = 'SolrService_Core';
+    private static $core_class = 'SilverStripe\FullTextSearch\Solr\Services\SolrService_Core';
 
     /**
      * Handle encoding the GET parameters and making the HTTP call to execute a core command

code/solr/stores/SolrConfigStore_File.php

@@ -25,7 +25,7 @@ class SolrConfigStore_File implements SolrConfigStore
             $worked = @mkdir($targetDir, 0770, true);
 
             if (!$worked) {
-                throw new RuntimeException(
+                throw new \RuntimeException(
                     sprintf('Failed creating target directory %s, please check permissions', $targetDir)
                 );
             }

code/solr/stores/SolrConfigStore_WebDAV.php

@@ -2,6 +2,9 @@
 
 namespace SilverStripe\FullTextSearch\Solr\Stores;
 
+use SilverStripe\FullTextSearch\Utils\WebDAV;
+use SilverStripe\FullTextSearch\Solr\Solr;
+
 /**
  * Class SolrConfigStore_WebDAV
  *