[MERGE] fix blackbox failures when run from windows executable

[Alexander Belchenko]

Mark Hammond пишет:
> Some of the blackbox tests are failing when run under a py2exe executable.

I'm risking to sound ungrateful but I have strong opinion that bzr.exe
should be distributed without test suite. Getting rid of any unnecessary files
from library.zip means shorter startup time and better user experience.

Currently (and ever) test suite only shows that everything works fine on Linux/Ubuntu.

There is too much places where test suite clearly shows bzr problems on windows,
and there is too much other problematic places not covered by test suite, but anyway they
are *real* *problems* for *real* *users*. And because these problems stays here for
years, fixing test suite should not be high priority. Mostly because test suite
on Windows don't running regularly opposing to PQM and therefore it's too easy
to broke something, create regressions, while on Linux everything seems fine.