Log Message:
Update to 4.18.0. From the changelog:

 -update broken link in FAQ.  Thanks: Stefan Kangas.
 -strip a few extra problematic (on non-Unix systems) characters when
 generating oldmail filenames; backslash was requested by Andy Ross.
 If upgrading and your current oldmail file contains any of these
 characters:
     \ ; < > |
 ... then rename it, replacing runs of one or more of those characters with
 a single "-".
 -improve clarity of message logged by getmail when an external program exits
 0 but getmail considers it failed because it wrote to stderr.  Thanks:
 Chris Dennis.