The following commits were cherry-picked from virtualenv's Git
repository from the develop branch:
0da2c50eafbf6841afad078e04aa873780905b99
e1ec5f3b9f5c3cfa533f5ce440d7ac251c14ad7d
da95f04065328a98d16bcad1e9ad0e89f3a41ebe
These should hopefully be part of virtualenv 1.8.3, whenever it is
released.