Add form section for changing the device hostname

[jstillwell]

Add a form section to the page that will post to a new api method to set the device hostname. It will:

• contain an input with a label of "Hostname"
• a submit button with a label of "Set Hostname"
• target is dummyframe to prevent page refresh
• update the UI with the new hostname

[jstillwell]

This is also likely going to be dependent on the library we use for templating. That issue needs to be handled first.

This turned out to be unnecessary

[graybushlabs]

Accidentally closed. There are some issues with getting the redirect to the new hostname working. I am going to look at templating engines first.