* include/db/postgresql.php, include/db/mysql.php, include/functions_db.php:
the function "get_system_time" and derivate functions in DB engines.
* include/functions_gis.php, include/functions_servers.php,
include/help/en/help_timesource.php, include/help/es/help_timesource.php,
include/help/ja/help_timesource.php, include/functions.php,
operation/agentes/estado_agente.php, operation/agentes/gis_view.php,
operation/gis_maps/render_view.php: added the SQL queries PostgreSQL
compatible, in this case with the function to get unix_timestamp.
git-svn-id: https://svn.code.sf.net/p/pandora/code/trunk@4058 c3f86ba8-e40f-0410-aaad-9ba5e7f4b01f
444148c60a