Add timestamp and readable time to verify

Answer https://github.com/keybase/keybase-issues/issues/270 by adding both a timestamp and a human-readable timestamp after the verify message.

The changes are made to the Iced CoffeeScript files. I compiled it locally to test it, but didn't commit generated code.

Screen capture:
![screen shot 2014-03-24 at 8 54 38 pm](https://f.cloud.github.com/assets/5694117/2507652/c075059c-b3c1-11e3-85cc-43260bd21b0c.png)