Further integration of backup into main Moodle.

The database checks/upgrades are now done on the main
admin page like the other modules.

The database files are now standard format .sql and .php files

PostgreSQL support was added - BUT HAS NOT BEEN TESTED YET!!

backup/db/postgres7.sql

@@ -0,0 +1,34 @@
+# THIS FILE IS UNTESTED!!!  
+# PLEASE HELP TEST/FIX IT AND CONTACT MARTIN OR ELOY!
+
+#
+# Table structure for table prefix_backup_files
+#
+
+CREATE TABLE prefix_backup_files (
+  prefix_backup_codetypepath_idx PRIMARY KEY,
+  backup_code integer NOT NULL default '0',
+  file_type varchar(10) NOT NULL default '',
+  path varchar(255) NOT NULL default '',
+  old_id integer default NULL,
+  new_id integer default NULL,
+) TYPE=MyISAM COMMENT='To store and recode ids to user and course files.';
+# --------------------------------------------------------
+
+CREATE INDEX prefix_backup_codetypepath_idx ON prefix_backup_files (backup_code,file_type,path)
+
+#
+# Table structure for table prefix_backup_ids
+#
+
+CREATE TABLE prefix_backup_ids (
+  prefix_backup_codenameid_idx PRIMARY KEY,
+  backup_code int(12) unsigned NOT NULL default '0',
+  table_name varchar(30) NOT NULL default '',
+  old_id int(10) unsigned NOT NULL default '0',
+  new_id int(10) unsigned default NULL,
+  info mediumtext,
+) TYPE=MyISAM COMMENT='To store and convert ids in backup/restore';
+
+CREATE INDEX prefix_backup_codenameid_idx ON prefix_backup_ids (backup_code,table_name,old_id)
+