Update libucl to latest version
Hide average speed from the progress meter

Showing two speeds is very confusing. While the average speed can be
interesting at the end of the download, when downloading it's the
current speed which helps identify peaks and stalls. This patch shows
the current speed only, and replaces it with the average when
finished.
As a side point, this leaves more room for package file name.
Custom ucl emitters

ucl_object_emit_sbuf: emit directly into a struct sbuf
ucl_object_emit_file: emit directly to a FILE *
Update copyright date
More copyright update
Fix logical errors in CUDF parser.
Fix misusage of sbuf