[MERGE] some fixes for selftest on win32

[John Arbash Meinel]

John Arbash Meinel has voted +1 (conditional).
Status is now: Approved
Comment:
I don't think we need an "if sys.platform == win32". We can just always 
set LANGUAGE, LANG, and LC_ALL to 'C'.

It doesn't break anything to do so, and I would really prefer to avoid 
platform specific behavior whenever possible.


And I think the test_external_diff_binary_lang_c can just do

old_env = {}
for lang in ('LANG', 'LC_ALL', 'LANGUAGE'):
   old_env[lang] = osutils.set_or_unset_env(lang, 'C')

and then later do:

for lang, old_val in old_env.iteritems():
   osutils.set_or_unset_env(lang, old_val)


For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C45F33684.9030104%40ukr.net%3E