Bug fix for pip 1.4 compatibility (workaround for PreviousBuildDirError)
Bug fix for pip 1.4 compatibility (workaround for PreviousBuildDirError)

theyoprst/pip-accel,pombredanne/pip-accel,matysek/pip-accel,paylogic/pip-accel,matysek/pip-accel,pombredanne/pip-accel,theyoprst/pip-accel,paylogic/pip-accel