title: Check if Date X is after Date Y with JodaTime
body: <p>I'm using the jodatime <code>DateTime</code> variable. I'd like to check if DateTime 'x' is after DateTime 'y'. The isAfter function only accepts a <code>long</code> parameter, not a <code>DateTime</code>, which I find very odd. Whats the best way to compare two <code>DateTime</code>s?</p>