expand system variables Unix style
This module is inspired by GNU bash's variable expansion features.
It can be used as an alternative to Python's os.path.expandvars
function.  A good use case is reading config files with the flexibility
of reading values from environment variables using advanced features
like returning a default value if some variable is not defined.

Maintainer: Denis Fondras <denis@openbsd.org>

WWW: https://pypi.python.org/pypi/expandvars
