Support for deviceName

[geekdave]

Currently for mobile devices, guacamole is aware of browserName, platform, version and (i think) deviceOrientation

We should also add support for deviceName which sets the resolution to match that of the device in question.

To see this in action, go to https://wiki.saucelabs.com/display/DOCS/Platform+Configurator#/

Click Selenium, iOS, then pick a device type and other options. /cc @Maciek416 @1un4r @archlichking

caps = {browserName: 'iphone'};
caps['platform'] = 'OS X 10.10';
caps['version'] = '9.2';
caps['deviceName'] = 'iPad Air';
caps['deviceOrientation'] = 'portrait';