Refactor incremental snapshots topics that failed to render downstream

The topics for triggering and stopping incremental snapshots was contained in a single file that used tagged region to render separate content for the SQL-based and NoSQL (MongoDB) connectors. This worked fine upstream, but the include directives that should incorporate the topics downstream do not work, and the content fails to render.

Rather than wrestle with this now, for the 2.1 release, I'm taking the simple route, and I've divided the content between separate files for the SQL-based, and MongoDB connectors. At some point when I have time, I might try to figure out what went wrong, but for now, this works.