Changes throughout Moodle to remove any reserved words from the

Moodle tables.

ie user -> userid in many tables, plus in user_students
   start -> starttime and end -> endtime

I've just done all this as carefully as I could ... I don't think
I missed anything but it's pretty intensive work and I'd be fooling myself
if I didn't think I'd missed a couple.

Note that this version should pretty much be able to bootstrap itself
using PostgreSQL now ... but this is untested

mod/quiz/db/postgres7.sql

@@ -52,7 +52,7 @@ CREATE TABLE quiz_answers (
 CREATE TABLE quiz_attempts (
   id SERIAL PRIMARY KEY,
   quiz integer NOT NULL default '0',
-  "user" integer NOT NULL default '0',
+  userid integer NOT NULL default '0',
   attempt integer NOT NULL default '0',
   sumgrades varchar(10) NOT NULL default '0.0',
   timestart integer NOT NULL default '0',
@@ -81,7 +81,7 @@ CREATE TABLE quiz_categories (
 CREATE TABLE quiz_grades (
   id SERIAL PRIMARY KEY,
   quiz integer NOT NULL default '0',
-  "user" integer NOT NULL default '0',
+  userid integer NOT NULL default '0',
   grade varchar(10) NOT NULL default '0.0',
   timemodified integer NOT NULL default '0'
 );