profiling: replace '+' markup of nested lines with indentation
The display of nested lines for hg --profile was very non-obvious and made it
look like sort didn't work.
The '+' immediately before CallCount was not related to the CallCount and did
not mean plus in any integer sense.
The '+' before module looked like a part of the module name and not like ascii
art.
Instead we now indent the subordinate module names to clearly show the
structure.
$ 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 [-ec] [TOPIC]
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