Add distlib's package_data to setup.py
Merge pull request #1245 from pfmoore/package_data

Add distlib's package_data to setup.py
Rename pip.vendor.* to pip._vendor.* to ensure it's obviously private
Merge pull request #1246 from dstufft/make-explicit-vendor-private

Rename pip.vendor.* to pip._vendor.* to ensure it's obviously private
changed the `pip bundle` deprecation notice so that:
- it says when the feature became deprecated
- for now, it doesn't specify when it will be removed until we're sure
- logs as a warning (with yellow color)