Update version number.

Update version number.
(timeclock-modeline-display): Mention timeclock-use-display-time
in explanatory message.
(timeclock-log): Suppress warnings when finding the log.  Don't
check for a nil project twice.  Run hooks after killing the
buffer (if applicable).
(timeclock-geometric-mean): Rename to `timeclock-mean' (it never
was geometric).  All uses changed.
(timeclock-generate-report): Support prefix argument.