pycompat: remove urlunquote alias
It is duplicated by urlreq.unquote and is unused. Kill it.
We retain the imports because it is re-exported via util.urlparse,
which is used elsewhere.
Since we no longer access attributes of urlparse at module load time,
this change /should/ result in that module reverting to a lazy module.
#require docutils gettext
$ $TESTDIR/check-gendoc ru
checking for parse errors