Not only can you compare objects at the object level and produce change scripts using Red Gate's SQL Compare, but you can also export your database objects into a folder hierarchy structured by object type, with one [objectname].sql creation script per object in these folders. The hierarchy of object types looks like this:
\Functions
\Security
\Security\Roles
\Security\Schemas
\Security\Users
\Stored Procedures
\Tables
You can use this to update your SVN repo and retain a running history of each item individually if you dump your scripts to the same root directory whenever you make changes.