Fix GH-1867: non-deterministic name for git editables on Python 3

Determine names_by_commit deterministically.
Add note about updating system path

Remind users to update system path since script does not. 

Well, at least on Windows it doesn't update PATH. Perhaps this should be qualified?
Merge pull request #1888 from patricktokeeffe/patch-1

Add note about updating system path
get-pip.py option examples

Conflicts:
	docs/installing.rst
break out the examples so we can add a qualifying footnote for --user installs

Conflicts:
	docs/installing.rst
Merge pull request #1944 from qwcode/critical_get-pip_docs

docs for get-pip.py options
Replaces spaces in username.
Merge pull request #1986 from matham/master

Replaces spaces in username.
Revert "Merge pull request #1986 from matham/master"

This reverts commit cb26c0b8cb00d18c75503ce4ee59a95a619e8189, reversing
changes made to bb8c7428ab40dde4af92e696ff518e82e214cd24.
Upgrade CacheControl to 0.10.4
Merge pull request #2044 from dstufft/update-cachecontrol

Upgrade CacheControl to 0.10.4
unit coverage for wrong-case
removed tag_svn_revision from setup.cfg

py.test tests/functional/test_install_user.py::Tests_UserSite::test_install_curdir_usersite
Merge pull request #2045 from bukzor/buck-tag-svn-revision

had to comment this out to make test pass:
Switch versioning from X.Y.Z to X.Y dropping the leading 1
Merge pull request #2047 from dstufft/new-versioning

Switch versioning from X.Y.Z to X.Y dropping the leading 1
Implement a pip self-check with to determine when it's out of date.

Initial work cribbed from PR 1214.
Normalize names in a URL

PyPI and Bandersnatch now normalize the project name in their
URLs. This change matches that and will reduce the number of
redirects we hit on PyPI and will reduce the need to hit /simple/
on a Bandersnatch mirror.
Merge pull request #2032 from bukzor/buck-coverage-1

unit coverage for wrong-case
Fix for Python 3.x, Refactor, and small changes