Looks like some users have found that it fixes their problem: https://issues.apache.org/jira/browse/CB-593
Options are: 1) Leave default as the iframe and tell users to change it if it causes them problems 2) Change the default to the iframeless version. It's a bit slower, but still quite fast. 3) Have the default be based on their OS version. I'd like to go with #2 because I think iframes have been the source of trouble for more bugs than just this CSS scrolling one (I've seen them mess up touch events on android before). Any objections?
