- Update package names that had -10.3 to -10.4
- Update conflicts/breaks/replaces of to include now also 10.3,
  just like 10.3 had the same relationship to 10.2
- Remove some old  (<< ${source:Version}) not needed anymore as we
  are not moving files around inside the 10.4 releases (at least yet).
- Ensure all plugins depend on server or client binaries from the same
  release so that they for sure are binary API compatible.