Remove duplicate web wallets services under mobile wallets

Live preview : http://bitcoinduplicate.us.to/en/choose-your-wallet

I think duplicate listing is confusing and should be reduced. All web wallets work on "Desktop" and "Mobiles" but it doesn't make sense to list them in all sub-categories.

I suggest that only minimally standalone apps ( able to store / backup private keys and sign transactions locally ) should be displayed under Desktop and Mobiles sections. This pull req also updates the Web wallets text to mention that they work on browsers and mobiles.