BUG-9482 Solr reindex error

Add catch exceptions to continue the index beside errors.
The found errors are logged.
Correct bug in unassigned users and groups.
Add functionality to reindex script:
- Add skip functionality to skip records to index
- Add definition of trunk size used to send docs to index server
- Add optimization utility to optimize index

workflow/engine/classes/class.searchIndex.php

@@ -331,6 +331,20 @@ class BpmnEngine_Services_SearchIndex
     $solr->commitChanges ($workspace);
   }
   
+  /**
+   * Optimize index changes
+   * @param string $workspace
+   */
+  public function optimizeIndexChanges($workspace)
+  {
+    G::LoadClass ('solr');
+  
+    $solr = new BpmnEngine_SearchIndexAccess_Solr ($this->_solrIsEnabled, $this->_solrHost);
+  
+    // commit
+    $solr->optimizeChanges ($workspace);
+  }  
+  
   /**
    * Call Solr server to return the list of paginated pages.
    * @param FacetRequest $solrRequestData