Merge branch 'release/1.7.2'
Merge branch 'release/1.8'
Updates virtualenv.py to distribute-0.6.28.tar.gz

This matches the virtualenv_support
Merge pull request #325 from michr/develop

Updates virtualenv.py to distribute-0.6.28.tar.gz
Update news.
Merge pull request #323 from pnasrat/develop

Unset __PYENV_LAUNCHER__ for frameworks.
Use a glob pattern for discovering the distribute and setuptools file name.
Updated changelog and bumped version.
Merge branch 'release/1.8.1'
Fixed travis config by adding a install section.
Updated pip to 1.2.1.
Bumped version up a notch and updated changelog.
Merge branch 'release/1.8.2'
Merge branch 'release/1.8.2' into develop
Make it possible to create a virtualenv from within a Python 3.3. pyvenv. Thanks Chris McDonough for the report.
Additional fix needed for creating virtualenv from pyvenv.
Fix activate.csh so that it will work in non-interactive environments
Update virtualenv.py script, AUTHORS, and changelog.
Add note in contributing docs about bin/rebuild-script.py
    give preference to <prefix>/lib64/pythonX.Y over
    <prefix>/lib/pythonX.Y on a 64bit system. when /lib
    is preferred over /lib64, it can mess up distutils/sysconfig
    and not get the correct values (e.g. sysconfig.get_config_var('CFLAGS'))
    which may result in a wrong build (e.g. -m32 on a 64bit system)

    patch virtual_install_main_packages() to prefer lib64_path
    when sys.maxsize > 2**32 by doing insert(0,...) rather than append.
    should fix issue #328