#299 Fix for bug 740457

[David J. Mellor]

The code in ArchRunner that attempts to extract a date
from a message's Date header invokes
email.Utils.mktime_tz, which in turn invokes Python's
time.mktime builtin. This builtin can throw either an
OverflowError or a ValueError exception if the date
cannot be converted. For example, the implementation of
mktime in glibc on Linux always returns -1 for dates
before the epoch, and on Linux an OverflowError
exception will be generatedin this case. The code in
ArchRunner was only handling ValueError exceptions,
with the result that messages whose dates were invalid
would be shunted on Linux instead of appearing in the
archive. The fix is simply to make the code in
ArchRunner handle both error conditions.

[David J. Mellor]

Patch for ArchRunner to fix bug 740457