Metacat

Added code to create new tables xml_path_index and xml_nodes_revisions...

Fixed bug in previous commit

Modified postgres script so that:
1. Foreign key for rootnodeid in xml_revision points to xml_node_revision table instead of xml_nodes
2. Added a new table xml_path_index which is used to index the paths specified by user in metacat.properties
3. Addes a new table xml_nodes_revision which stores the nodes of old revisions and deleted documents...

Removing code added for creating nodedata column in xml_index table

Made changes in the sql scripts to create new tables xml_returnfield and xml_queryresult

Modified xmltables to add nodedata as part of the xml_index tables.

Modified database creation sql code so that in xml_nodes, nodedatanumerical coulmn is added.

New schema changes, including upgrade scripts. Includes renamed postgres
scripts.