Docs: KS_DEV_SITES
Move venv_hook into package so it is installed
Flip order of KS_DEV_SITES
Site constructor absorbs ENOENT OSError

This seemed like an unnecessary detail to expose.
`dev` requires one of the discovered sites to be a venv
Site.which('pip') to find executables
Include venv_hook in MANIFEST.in so it gets installed
Fix formatting of error in venv_hook
Adjust venv_hook to work in new location
`dev --create` to auto-create
Provide dev-shell function
`dev bash` refuses to run
dev-deactivate to get you back to "normal"
Fix indent around try
Log envvars back to the KS variants
Deal with OS X's Python frameworks

Wherein the executable has an uppercased name.
Replace {platform_spec} in *.pth files
Named freezes can be unfrozen in a context manager
Look for more examples of non-python executables
Also check for site.py, as Python actually does