tests/test-demandimport

refactor version code

- simplify version detection code
- move detection code into setup.py
- move version reading function into util.py
- drop version.py code

This makes hg more closely follow its own recommendation of how to deal with
versioning your builds: use hg id in your build script.

#!/usr/bin/env python

from mercurial import demandimport
demandimport.enable()

import re

rsub = re.sub
def f(obj):
    l = repr(obj)
    l = rsub("0x[0-9a-fA-F]+", "0x?", l)
    l = rsub("from '.*'", "from '?'", l)
    return l

import os

print "os =", f(os)
print "os.system =", f(os.system)
print "os =", f(os)

from mercurial import util

print "util =", f(util)
print "util.system =", f(util.system)
print "util =", f(util)
print "util.system =", f(util.system)

import re as fred
print "fred =", f(fred)

import sys as re
print "re =", f(re)

print "fred =", f(fred)
print "fred.sub =", f(fred.sub)
print "fred =", f(fred)

print "re =", f(re)
print "re.stdout =", f(re.stdout)
print "re =", f(re)