tests: compatibility fix.
'touch -d *' doesn't work on Mac OS X. In order to prevent this from
occuring again, a check for the case is added to 'check-code.py'.
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.