Option in database.yaml to specify XMigra metadata schema (i.e. namespace) in DB

[rtweeks]

The database.yaml file should support an option allowing specification of the schema name (rather than the hard-coded default of xmigra) within which the XMigra version tracking metadata is stored. In addition to general flexibility, this allows different parts of the same database to be managed by different XMigra schema source file trees.

[rtweeks]

This is another one of those "you'll be sorry I added it" situations :(

If XMigra had this "feature" it would allow two separate XMigra projects to co-exist in the same database -- if they follow certain rules. If they break the rules, then there is no guarantee that the upgrade scripts will work, even if they worked on a test box. Here's the bad news: the only real reason to use this "feature" is to break those rules.

[rtweeks]

On further consideration, this could be done (if done carefully) by use of stopping points (#36), so that issue blocks this one.