PyPy's _lsprof module doesn't export a "profiler_entry" symbol. This
patch treats the symbol as optional and falls back to verifying the
attribute is present on the first entry in the collected data as
part of validation.
There is a chance not every entry will contain the requested sort
attribute. But, this patch does unbust lsprof on PyPy for the hg
commands I've tested, so I assume it is sufficient. It's certainly
better than the ImportError we encountered before.
As part of the import refactor, I snuck in the addition of
absolute_import.
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.
This should be faster and more future-proof. Calls where the result is to be
sorted using util.sort() have been left unchanged. Calls to .items() on
configparser objects have been left as-is, too.