Add ElementPath to the list of package ignored by demand import
The bzrlib try to import the ElementPath module but had a fallback in
case the import fails. Lazy import of this module leads to later
failure.
The bzrlib is used by the convert extension.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.