first round of presentation layer updates

I've updated the index (the copy is my own doing...'just put some text there that seemed useful), and Register page, added CSS, images, and a bit of responsive layout. 

In the Register page I also include an example of a input field error...adding a CSS class to the label and including a <span> with error text is all that's needed. 

Hopefully I didn't miss anything here...this is my first pull request & working w/ a Java project in Git, so if I'm in noob form anywhere pls lend me your patience.  =P

...Adrian