Fix for demandimport.py and Windows compiled version.
From Shun-ichi Goto in BTS issue 457 http://www.selenic.com/mercurial/bts/msg2780
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
See http://www.selenic.com/mercurial/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.