Allow backslashing curly braces to prevent expansion
Allow backslashing curly braces to prevent expansion

e.g.: commands=echo \{posargs\} = {posargs}

--HG--
branch : allow_backslash_escape_curly_braces_msabramo_2

Avira/tox,gaborbernat/tox,tox-dev/tox,loechel/tox,selimb/tox