subrepo: make update -C clean the working directory for svn subrepos
This makes 'hg update --clean' behave the same way for both kinds of
subrepositories. Before Subversion subrepos did not take the clean
parameter into account, but just updated to the given revision and
merged uncommitted changes into that.
$ echo 'raise Exception("bit bucket overflow")' > badext.py
$ abspath=`pwd`/badext.py
$ echo '[extensions]' >> $HGRCPATH
$ echo "gpg =" >> $HGRCPATH
$ echo "hgext.gpg =" >> $HGRCPATH
$ echo "badext = $abspath" >> $HGRCPATH
$ echo "badext2 =" >> $HGRCPATH
$ hg -q help help
*** failed to import extension badext from $TESTTMP/badext.py: bit bucket overflow
*** failed to import extension badext2: No module named badext2
hg help [TOPIC]
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