tox-1.7.0: many bug fixes and little improvements

[holger krekel]

Just released tox-1.7.0 (finally), the generic virtualenv-based test runner
for Python.  It contains a lot of fixes and improvements although there 
are some bugs remaining.  While a lot of pull requests are thankfully offered
i could use some more co-maintaining/reviewing to allow for some 
faster progress.

Anyway, to install to 1.7.0 :

    pip install -U tox
    

and to look at the docs:

    https://testrun.org/tox/latest/

have fun,
holger

1.7.0
---------

- don't lookup "pip-script" anymore but rather just "pip" on windows 
  as this is a pip implementation detail and changed with pip-1.5.  
  It might mean that tox-1.7 is not able to install a different pip 
  version into a virtualenv anymore.

- drop Python2.5 compatibility because it became too hard due
  to the setuptools-2.0 dropping support.  tox now has no 
  support for creating python2.5 based environments anymore
  and all internal special-handling has been removed.

- merged PR81: new option --force-dep which allows to 
  override tox.ini specified dependencies in setuptools-style.
  For example "--force-dep 'django<1.6'" will make sure
  that any environment using "django" as a dependency will 
  get the latest 1.5 release.  Thanks Bruno Oliveria for 
  the complete PR.
  
- merged PR125: tox now sets "PYTHONHASHSEED" to a random value
  and offers a "--hashseed" option to repeat a test run with a specific seed.
  You can also use --hashsheed=notset to instruct tox to leave the value
  alone.  Thanks Chris Jerdonek for all the work behind this.

- fix issue132: removing zip_safe setting (so it defaults to false)
  to allow installation of tox
  via easy_install/eggs.  Thanks Jenisys.

- fix issue126: depend on virtualenv>=1.11.2 so that we can rely
  (hopefully) on a pip version which supports --pre. (tox by default
  uses to --pre).  also merged in PR84 so that we now call "virtualenv"
  directly instead of looking up interpreters.  Thanks Ionel Maries Cristian.
  This also fixes issue140.

- fix issue130: you can now set install_command=easy_install {opts} {packages}
  and expect it to work for repeated tox runs (previously it only worked
  when always recreating).  Thanks jenisys for precise reporting. 

- fix issue129: tox now uses Popen(..., universal_newlines=True) to force 
  creation of unicode stdout/stderr streams.  fixes a problem on specific
  platform configs when creating virtualenvs with Python3.3. Thanks
  Jorgen Schäfer or investigation and solution sketch.

- fix issue128: enable full substitution in install_command,
  thanks for the PR to Ronald Evers

- rework and simplify "commands" parsing and in particular posargs
  substitutions to avoid various win32/posix related quoting issues.

- make sure that the --installpkg option trumps any usedevelop settings
  in tox.ini or

- introduce --no-network to tox's own test suite to skip tests
  requiring networks

- introduce --sitepackages to force sitepackages=True in all
  environments.   

- fix issue105 -- don't depend on an existing HOME directory from tox tests.