Delete selected tests from tree hierarchy

The action deletes all selected tests (check box activated) in the test run tree. When test runs are checked, all tests defined in the test run are deleted. When no check box is activated in the list, the currently selected entry is deleted, i.e. in order to delete a single test or a single test run, the corresponding line has to be selected, only, before clicking the button.

In order to obtain a warning dialog before deleting each selected tree entry, the option variable ASK_BEFORE_DELETE has to be set to true (TestBrowser ini- or configuration file). Than, a deletion confirmation is required by popping up a deletion dialog.