fixes a bug where a Basic auth digest header can get encoded with newlines inside

--HG--
extra : amend_source : 0f58aa917ebc71efd2904638fac3838fd0b0e4dd

Issue #101 and tweak legacy fallback

make sure they are in the paths for the legacy tests (why did it work before).
Let us hope that svn is not in that directory...

   (Fixed unexpected deprecation warning from prombredanne)
Also removed the warning from fallback, only a deprecation warning is issued.
Environment.py whitespacing
Created a specialized command executor for tests in Environment.py
Legacy Test in test_egg_info now supresses the deprecation warning.
PythonPath is now explicitly controlled to allow setup.py test on clean
   python installations.  *Fixes Issue #101*
Moved some dummy svn tests from test_sdist to test_egg_info since
   they are egg_info tests.
Downgraded a with statement in a test since we haven't offically dropped
   2.4 support, however, maybe it is time.
Added a test case to ensure no extranuous output on sdist with a simple
   dummy package without rev ctrl.

Added a test to run egg_info on a dummy SVN package.
Added a second similar test that invokes the legacy code.

replaced fsencode with decode_as_string - decoded utf8 or console input to
decode_as_string should be called on encoded string before joining
BUG_FIX - It would seem that there is a issue wiht the legacy file listing
  which this commit fits.  I have no clue how any of the other stuff would
  had even worked.

Removed verbose warning from svn_utils.py

Add svn test data