Ensure that the uninstall helper for Windows passes the proper
flags to pip to prevent it from checking PyPI if the pip that
we're currently attempting to uninstall is the latest verison.

The 3.4rc2 Windows uninstaller would fail if pip had been updated
to a version that didn't match the version installed by ensurepip.
This skip is no longer treated as an error, so an updated pip ends
up being handled like any other pip installed package and is left
alone by the CPython uninstaller.

The 3.4rc2 Windows uninstaller would fail if pip had been updated
to a version that didn't match the version installed by ensurepip.
This skip is no longer treated as an error, so an updated pip ends
up being handled like any other pip installed package and is left
alone by the CPython uninstaller.

- now also allows POSIX installation with SSL/TLS missing
- a goal for pip 1.6 is to allow local use without SSL/TLS

- now also allows POSIX installation with SSL/TLS missing
- a goal for pip 1.6 is to allow local use without SSL/TLS

ensurepip now sets PIP_CONFIG_FILE to os.devnull before
import pip from the wheel file. This also ensures venv
ignores the default settings when bootstrapping pip.