With a pruned wallet possible in master I believe we should expose the option in the GUI.

The Main tab in preferences will offer a chance to toggle the node type and size.
<img width="612" alt="pruning_gui_off" src="https://cloud.githubusercontent.com/assets/216917/8766147/834fb842-2e2c-11e5-94b0-c342132243bf.png">
<img width="612" alt="pruning_gui_on" src="https://cloud.githubusercontent.com/assets/216917/8766148/8351a0c6-2e2c-11e5-841b-af02fd77ff44.png">

The prune size UI should not permit sizes less than 550.

{
    proxyType proxy;
    std::string strProxy;
    QString strDefaultProxyGUI;
    model->node().getProxy(NET_IPV4, proxy);
    strProxy = proxy.proxy.ToStringIP() + ":" + proxy.proxy.ToStringPort();
    strDefaultProxyGUI = ui->proxyIp->text() + ":" + ui->proxyPort->text();
    (strProxy == strDefaultProxyGUI.toStdString()) ? ui->proxyReachIPv4->setChecked(true) : ui->proxyReachIPv4->setChecked(false);
    model->node().getProxy(NET_IPV6, proxy);
    strProxy = proxy.proxy.ToStringIP() + ":" + proxy.proxy.ToStringPort();
    strDefaultProxyGUI = ui->proxyIp->text() + ":" + ui->proxyPort->text();
    (strProxy == strDefaultProxyGUI.toStdString()) ? ui->proxyReachIPv6->setChecked(true) : ui->proxyReachIPv6->setChecked(false);
    model->node().getProxy(NET_TOR, proxy);
    strProxy = proxy.proxy.ToStringIP() + ":" + proxy.proxy.ToStringPort();
    strDefaultProxyGUI = ui->proxyIp->text() + ":" + ui->proxyPort->text();
    (strProxy == strDefaultProxyGUI.toStdString()) ? ui->proxyReachTor->setChecked(true) : ui->proxyReachTor->setChecked(false);
}
ProxyAddressValidator::ProxyAddressValidator(QObject *parent) :