[Nitro] OG draft patch: Eliminate the duplicate query seen in calls to og_create_schema

[Mark Van De Vyver]

Hi Devs,

Attached is a draft patch that should eliminate the duplicate query
when og_create_schema is run.  I guess this is likely only to have
hurt your performace if you have to create lots of tables (my use
case), have a very slow connection, or a DB that is under heavy load?

Anyway it was an interesting exercise to try and come to grips with
some of the OG code - I don't fully understand the different roles of
the different SQLEnchant* modules....

This is my first open source patch so don't expect too much :)

Seriously, _when_ the guts of this change is OK, then I'll dump all
the commented code and submit a cleaner patch.
I've tested with the Sqlite and Mysql stores/adapters.

Hopefully a more constructive email than some of the noise I've been
sending lately - steep learning curve :)

Mark