Revert Virtual Time related references.
Revert Virtual Time related references.

mithro/python-datetime-tz,davidfraser/python-datetime-tz,davidfraser/python-datetime-tz,dave42/python-datetime-tz,j5int/python-datetime-tz,matthewhampton/python-datetime-tz,j5int/python-datetime-tz,mithro/python-datetime-tz