Bug 123496 [IDE] Use operation validation API for IDE actions
We should use the Resources/Core operation validation API in the IDE actions for manipulating resources.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/DeleteResourceAction.java
*
     * @param resources the selected resources
     * @return <code>true</code> if the resources contains only non-projects, and 
     *  <code>false</code> otherwise
     */
    private boolean containsOnlyNonProjects(IResource[] resources) {
        int types = getSelectedResourceTypes(resources);
        
        if (types == 0)
            return false;
        
        return (types & IResource.PROJECT) == 0;
    }
    /**
     * Returns whether the selection contains only projects.
     * 
     * @param resources the selected resources
     * @return <code>true</code> if the resources contains only projects, and 
     *  <code>false</code> otherwise
     */
    private boolean containsOnlyProjects(IResource[] resources) {
        int types = getSelectedResourceTypes(resources);
        
        return types == IResource.PROJECT;
    }
    
    /**
     * Creates and returns a result status appropriate for the given list of exceptions.
     * @param exceptions The list of exceptions that occurred (may be empty)
     * @return The result status for the deletion