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
while (itr.hasNext()) {
            Capability cap = (Capability) itr.next();
            String[] ids = registry.getMembershipSetIds(cap);
            for (int j = 0; j < ids.length; j++) {
                memberships.put(ids[j], cap);
            }
        }
    }
    /**
     * Handle the case of a capability being checked
     * by ensuring the action is allowed and the prerequisite
     * capabilities are also checked.
     */
    private void handleCapabilityChecked(Capability capability) {
        
        if (isDisabledCapability(capability)) {
            MessageDialog
                    .openWarning(
                            checkboxViewer.getControl().getShell(),
                            IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_errorTitle,
                            NLS.bind(IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_disabledCapability, capability.getName()));
            checkboxViewer.setChecked(capability, false);
            return;
        }
        
        if (!capability.isValid()) {
            MessageDialog
                    .openWarning(
                            checkboxViewer.getControl().getShell(),
                            IDEWorkbenchMessages.ProjectCapabilitySelectionGroup_errorTitle,