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/dialogs/ProjectCapabilityEditingPropertyPage.java
if (prereqs.contains(cap.getId())) {
                MessageDialog
                        .openWarning(
                                getShell(),
                                IDEWorkbenchMessages.ProjectCapabilityPropertyPage_errorTitle,
                                NLS.bind(IDEWorkbenchMessages.ProjectCapabilityPropertyPage_capabilityRequired, caps[i].getName()));
                return;
            }
        }
        IStatus status = reg.validateCapabilities(caps);
        if (!status.isOK()) {
            ErrorDialog
                    .openError(
                            getShell(),
                            IDEWorkbenchMessages.ProjectCapabilityPropertyPage_errorTitle,
                            IDEWorkbenchMessages.ProjectCapabilityPropertyPage_invalidSelection,
                            status);
            return;
        }
        String[] natureIds = new String[1];
        natureIds[0] = cap.getNatureId();
        ICapabilityUninstallWizard wizard = cap.getUninstallWizard();
        if (wizard == null)
            wizard = new RemoveCapabilityWizard();
        if (wizard != null) {
            wizard.init(PlatformUI.getWorkbench(), StructuredSelection.EMPTY,
                    getProject(), natureIds);
            wizard.addPages();
        }
        if (wizard.getStartingPage() == null) {