[Libguestfs] URI Handling Patch

I have written a patch (please see attached) which fixes both of these bugs: https://bugzilla.redhat.com/show_bug.cgi?id=1092583 https://bugzilla.redhat.com/show_bug.cgi?id=1232477 By default, when saving a URI using xmlSaveUri it escapes everything in the URI. QEMU doesn't want anything escaped, so now I unescape everything after the URI is generated. Unfortunately there's no flag to change the default behavior. The other problem was that only the "path" portion of the URI struct was being used to indicate the path. That's natural enough, but that practice is what was dropping the query string. The query string is kept separately from the path. I now concat the query string back onto the URI with a separating '?'. I've successfully mounted remote vhds in Azure with this new code, and the basic set of tests pass. If there's anything else I can do by way of verification, please let me know. -- Gabriel