The requirement is to provide a mechanism for query highlighting and allowing it
to be persistent.

Modifications are to drawmap.php and map_query.php from the common folder
(php_utils cvs)

drawmap.php already contains the code necessary to do a drawQuery if called
appropriately, but there is no way to make this query persistent.

The modifications will make use of the mapscript functions for loadQuery and
saveQuery.  When drawmap is called with gszPersistentQuery=1 and run_query=1 and
appropriate query coordinates, it will run a query, draw the map using
drawQuery, and save the query results, if any, to a well known file in the
session directory.  

The file is query_results.qry.

If drawmap is called with run_query=1 and gszPersistentQuery=0 it will delete
the query_results.qry file if it exists.

If drawmap is called in regular draw mode (no query) it will check for the
existence of query_results.qry and load it if it is available.

This means that any widget can create persistent query results for display on
the map by creating this file using 

$oMap->saveQuery( getSessionSavePath()."/query_results.qry" );

If a persistent query is requested through drawmap and the query produces no
results, then query_results.qry will be deleted if it exists.  This requires a
change to map_query.php.