- The table_priv column of table_privs table was altered to a enum type
with fewer enums causing the SHOW/CREATE VIEW grants to be truncated.
- Improved comments and moved all declarations for table_privs, column_privs
and proc_privs to one section for each table making it easy to see hat alterations
are performed on each table
- Reduced the number of ALTER's slightly, but as this is an upgrade script we need
to take all possibilites into account.
