Guest network support for Gargoyle

Eric,

I would like to contribute support for guest networking in Gargoyle, something that has been asked for by many. See the [applicable thread](http://www.gargoyle-router.com/phpbb/viewtopic.php?f=14&t=6358#p25768) on the Gargoyle forums. The UI mirrors that of the AP network for SSID, encryption, SSID broadcasting and client isolation. By default, clients are isolated. Also, it is possible to only set a guest network on one of the frequencies when the AP is in dual mode.

As I posted there, it seems (from posts from pbix) that the driver you use for Broadcom chipsets won't support that, so for now non-Atheros chipsets will not show the guest network display. This is controlled by the variable `gns` (guest network supported) in `setWifiVisibility()` in the `basic.js` file.

Let me know if you have any questions.

![screen shot 2014-11-10 at 8 12 28 pm](https://cloud.githubusercontent.com/assets/2025939/5017675/c564f0b2-6a64-11e4-9b8f-1d7ef051e6ca.png)
![screen shot 2014-11-10 at 8 13 02 pm](https://cloud.githubusercontent.com/assets/2025939/5017684/d1c1be8a-6a64-11e4-8486-33ba80dff444.png)
![screen shot 2014-11-10 at 8 13 26 pm](https://cloud.githubusercontent.com/assets/2025939/5017686/d3b1cd20-6a64-11e4-87ad-6c7406e44407.png)
![screen shot 2014-11-10 at 8 13 42 pm](https://cloud.githubusercontent.com/assets/2025939/5017690/d588eda4-6a64-11e4-8699-12f0ae84c8e4.png)