Simpler settings

Host and Path are safer (and more accurately) derived automatically than by user edit. 

Since host is always derived from URL, and path is always the install path, lets simplify the admin panel and remove one more possibility for misconfiguration.

(note, if you *really* want to change these, and you know what you are doing, you can set it in config.ini, but I can't imagine a situation where you'd ever want to do this)