Metacat

Consider mutithread issue there.

use the sharing code from the metacat-common.

Move this class to the metacat-common.

Use an update method to replace the insert and update methods in the SolrIndex class.

Add code to generate index during the servlet initialization.

Use the Identifier object rather than String as the key to get the system metadata and object path.

Add a junit test for the IndexGenerator class.

Add a new class which will generate index for the ids.

Add code to get all doc ids in the solr server.

Add a remove(List) method in the class and an obsoletes list parameter in the update method.