Map remote projects by path as well.

Sometimes we want to navigate around a remote project, so this is needed.
Bump to new pom-util snapshot.
Use shipped sbt-pom-util.
Cope with project version changes.

Immutability makes this a bit pesky. Instead of just updating things in place,
we have to unload the current resolved project state, update the database and
re-resolve the project with its new version.