[turba] table definition w/oci8

[Liam Hoekenga]

> Okay, check the oci8_create.sql that I just added to Turba...

Oracle doesn't have a TEXT column type, so the text columns either should be
CLOBS or VARCHAR2(4000).  The VARCHAR columns should probably be VARCHAR2 (as
VARCHAR is provided for compatibility, but VARCHAR2 is the real column type).

I know this isn't specifically a Horde problem, but the whole 4000 character
Oracle string limit  sucks.

Liam