Modify add pip_zip to sys.path method
Merge pull request #1514 from dongweiming/develop

Modify add pip_zip to sys.path method
'pip wheel' should download wheels, when it finds them
when file urls have hash fragments, check it
Merge pull request #1524 from qwcode/download_wheels

'pip wheel' should download wheels, when it finds them
fixes for downloading wheels (Issue #1112)
Merge pull request #1527 from qwcode/wheel_deps

fixes for downloading wheels (Issue #1112)
update changelog
update changelog
remove `pip wheel` warnings due to merge of #1524
Simplify __main__ logic

runner.py seemed to exist for the sole function of containing
a simple function that was called by __main__.py.

I've simply removed that file with its function moved into
__main__.py itself; no functionality should be expected to change.
Make main even simpler
Special case os.devnull for PIP_CONFIG_FILE to mean 'no config file'
Merge pull request #1544 from pfmoore/devnull

Special case os.devnull for PIP_CONFIG_FILE to mean 'no config file'
'pip wheel' should download wheels, when it finds them

Conflicts:
	pip/commands/wheel.py
	pip/download.py
	pip/req/req_set.py
	pip/wheel.py
when file urls have hash fragments, check it
fixes for downloading wheels (Issue #1112)

Conflicts:
	pip/req/req_set.py
cherry-pick fixes
update changelog
Revert "Use Travis to handle the Matrix"

This reverts commit 01894aee7be04fb0756f4e73a462ccf5ae2c886f.