Add media query for handheld devices

This media query aims to make the web client more useable on phones. It removes the toolbar and chat-input icons and makes text larger and easier to read.
Increase tab size on handheld devices

Make tabs bigger on phones for easier tapping. Also make the chat inputbox bigger.
Change media queries to target devices more accurately
Merge pull request #84 from coldstorm/css-tweaks

CSS tweaks