Allow doloadinfo() to return more than the stock 2K of info.
At least for TCP based calls. We will need this for long-ish delta chains. I didn't think this warranted a version number bump even though it is possible that an old MFS that makes a UDP-based call will only wind up getting the first line (image). The reasoning here is that MFSes that old could only handle one line anyway in rc.frisbee!