This fixes an issue with tox/virtualenv/pip where the pip and wheel
shebang lines were wrapped with a quote " that prevents the command
from executing.
66e4805271/distlib/scripts.py (scripts.py-66)
I confirmed that with the updated distlib I was able to create a
virtualenv, and then install the updated `pip` into it.
```
virtualenv --no-wheel --no-pip --no-setuptools --python=jython jython.env
jython -c 'import sys, pip; sys.exit(pip.main(["install", "--ignore-installed"] + sys.argv[1:]))' pip
```
```
$ pip list
decorator (4.0.9)
ipython (4.1.1)
ipython-genutils (0.1.0)
path.py (8.1.2)
pexpect (4.0.1)
pickleshare (0.6)
pip (8.0.2)
ptyprocess (0.5.1)
py (1.4.31)
pytest (2.8.7)
requests (2.9.1)
setuptools (20.0)
simplegeneric (0.8.1)
simplejson (3.8.1)
six (1.10.0)
traitlets (4.1.0)
wheel (0.29.0)
```
Aside: The process for tracking and updating _vendor libs should be streamlined.
The Makefile blows away modified code, making it a manual process to update
vendored libs.