Currently, the `groups` and `excludedGroups` work like:
This doesn't cover many usecases. For instance, if the groups overlap.
Example: user needs to run only EJB tests under security manager, while only some EJB tests can run under security manager.
In such case, this is needed:
The suggestion is to introduce two new params:
They would switch AND and OR behavior.
Union would be the default (preserving current behavior).
Would be implemented in a filter, see: