[MERGE] BZR_LOG env variable controls location of .bzr.log.

[Alexander Belchenko]

Robert Collins пишет:
> Robert Collins has voted resubmit.
> Status is now: Resubmit
> Comment:
> I think that the trace.enable_default_logging() call should honour the 
> new environment variable, for other programs using bzrlib.

My first patch was used BZR_LOG inside trace.py module. But John Meinel wrote at 28.01.2008:

 > It seems to me that it should be done by the 'bzr' code, not inside the bzrlib code.

So it was changed this way. Can you and John agreed on your opinions, please?

> also the new environ variable needs to be added to the list santised by 
> the test suite.

It's already done:

--- bzrlib/tests/__init__.py	2008-01-29 08:21:19 +0000
+++ bzrlib/tests/__init__.py	2008-02-06 10:07:17 +0000
@@ -1202,6 +1202,7 @@
              'BZREMAIL': None, # may still be present in the environment
              'EMAIL': None,
              'BZR_PROGRESS_BAR': None,
+            'BZR_LOG': None,
              # SSH Agent
              'SSH_AUTH_SOCK': None,
              # Proxies