add detection of proper rtmpdump host for DR
Make SvtPlay behave better on some streams:
- some streams start on fragments other than 1.  This is a first simple attempt to parse (and remember and calculate) the fragrun tables.  It's probably broken for more complex streams, but *should* work for simpler ones.
- deal with URLs that already have a query string in them for SvtPlay
- update hdcore parameter to the current value of '2.11.3'
- improve some error messages to provide URL information when a URL fails