New field on course_modules called "indent" ... this is an integer

that tells us how far to indent the activity when it is displayed.

This gives us some more flexibility on the course outline to
arrange things as we might like them, into subtopics etc

Backup/restore is updated as well.

There is also a bit more robustness in course/mod.php

lib/db/postgres7.sql

@@ -62,6 +62,7 @@ CREATE TABLE prefix_course_modules (
    added integer NOT NULL default '0',
    deleted integer NOT NULL default '0',
    score integer NOT NULL default '0',
+   indent integer NOT NULL default '0',
    visible integer NOT NULL default '1'
 );