Bug 126779 [IDE] Removed deprecated project capabilities API and implementation
It was created then deprecated before 2.0 shipped. As has never been API and we don't use it we should delete it.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/misc/ProjectCapabilitySelectionGroup.java
Capability[] prereqCapabilities;
                prereqCapabilities = registry.findCapabilities(prereqIds);
                for (int i = 0; i < prereqCapabilities.length; i++) {
                    
                    
                    if (prereqCapabilities[i] == null
                            || isDisabledCapability(prereqCapabilities[i])
                            || !prereqCapabilities[i].isValid()) {
                        MessageDialog
                                .openWarning(
                                        checkboxViewer.getControl().getShell(),
                                        IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_errorTitle,
                                        NLS.bind(IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_missingPrereqs, capability.getName(), prereqIds[i]));
                        checkboxViewer.setChecked(capability, false);
                        return;
                    }
                    
                    
                    ids = registry.getMembershipSetIds(prereqCapabilities[i]);
                    for (int j = 0; j < ids.length; j++) {
                        Capability member = (Capability) memberships
                                .get(ids[j]);
                        if (member != null && member != prereqCapabilities[i]) {
                            MessageDialog
                                    .openWarning(
                                            checkboxViewer.getControl()
                                                    .getShell(),
                                            IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_errorTitle,
                                            NLS.bind(IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_membershipPrereqConflict, new Object[] {capability.getName(), prereqCapabilities[i].getName(), member.getName()}));
                            checkboxViewer.setChecked(capability, false);