convert: clear the dirstate before a conversion, invalidate it afterwards
Clearing it before the conversion protects us from whatever data were
there (file copies in particular).
Invalidating it after the conversion avoids writing a possibly
inconsistent dirstate to disk.
#!/bin/sh
echo '[Section]' >> $HGRCPATH
echo 'KeY = Case Sensitive' >> $HGRCPATH
echo 'key = lower case' >> $HGRCPATH
hg showconfig Section