[Dillo-dev] abort on read failure

I was recently in an environment with a very weak connection. With most sites, if I didn't get a full page, lsof would show the connection still open and just sitting there. Some sites _would_ close the connection, but unfortunately dillo wouldn't give the user any indication that further waiting was pointless. I just committed some code that aborts the connection on read failure. It also gives a status msg to the user (though status messages are imperfect, as discussed last month). The case where no data was received could bear further improvement, but I had limited time and improved what I needed most. It got a week or so of "free" testing in that bad environment, and hasn't given me any trouble since then in more solid environments.