enable iPad fix on iPhone user agent

There is code for basic support for iPads. However, the current code only detects iPads, not iPhones. I ran into an issue where I needed to issue some commands into my tty.js setup and didn't have a computer nearby. This PR applies the same iPad fix to iPhones. (When using a soft keyboard, we have to focus a dummy input text to show the onscreen keyboard.) 

I tested with my iPhone 5 iOS 7.0.4 on Safari and it works great. 

I wasn't sure if we wanted to keep `isIpad` and `isIphone` separate or combine them into one variable called `isiOS` since iPad and iPhone get the same `fixIpad(document);`.