change uuid length in db from 128 to 40

UUID length in the DB for grouper cols has been varchar 128.
Not sure why this was chosen originally since we use standard 32 char uuids (and sometimes with some dashes).

Anyways, this is a problem for 2 reasons:

1. Mysql cant have a combined index size of 1024 (maybe less in some versions)
2. If you are doing in-memory databases, sometimes it treats varchars as chars

In the table where we have an index larger than 1024, if we make the uuid's smaller, it fixes the issue. Shilen, TomZ and I have been discussing making those cols smaller (they are all new cols for v1.5). However, I think we should make all uuid's smaller. The DDLutils currently will ignore columns which are a different size than they should be. So if we change the definitions so that they are all size 40 (32 + 4 dashes + a little lee-way), then if you have an existing schema it will leave it the way it is, and if you are making a new schema, then it will make it size 40. If you are importing from old to new, there shouldnt be any existing IDs larger than 40 so you should be all good.

Chris