Da monster-commit of blocks version 2!

Code based on the work of Daryl Hawes for the blog module. Thanks, Daryl!

Please test the hell out of it as it's sure to have issues that need to be
ironed out.

lib/db/postgres7.sql

@@ -17,7 +17,6 @@ CREATE TABLE prefix_course (
    format varchar(10) NOT NULL default 'topics',
    showgrades integer NOT NULL default '1',
    modinfo text NOT NULL default '',
-   blockinfo varchar(255) NOT NULL default '',
    newsitems integer NOT NULL default '1',
    teacher varchar(100) NOT NULL default 'Teacher',
    teachers varchar(100) NOT NULL default 'Teachers',