daemon: Abort when failing to chdir()

We don't want to run in daemon mode if we don't know where we're
running. This patch makes sure that our attempt to chdir to / (if we
don't dump core) or $HOME (if we do) is successful. Otherwise, we abort.

Signed-off-by: Anton Lofgren <alofgren@op5.com>
Merge pull request #73 from catharsis/abort-on-failed-chdir

daemon: Abort when failing to chdir()