[FIX] Trade URI: Actually save the issuer parameters & allow resolve Ripple name


More specifically, this fixes the following bug:
>When I click on this link, it doesn't load the right orderbook for me- for me it
>loads the SnapSwap USD/XRP orderbook.
>
>https://staging.ripple.com/client/#/trade?type=buy&first=USD:~Bitstamp&second=XRP&amount=0.0001&price=0.0027&max=0.1
>
>I then tried to put Bitstamp's Ripple address in instead of the Ripple name, and
>it didn't work either. It still loaded the SnapSwap USD/XRP orderbook.
>
>https://staging.ripple.com/client/#/trade?type=buy&first=USD: rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B&second=XRP&amount=0.0001&price=0.0027&max=0.1