fixed exception handling - closes #173

Signed-off-by: Petr Kubat <pkubat@redhat.com>
Signed-off-by: Jiri Moskovcak <jmoskovc@redhat.com>
add docstrings, remove global variable - related #171

please disregard previous version of the patch
clean_up function has to stay global because of install-debuginfo in abrt

Signed-off-by: Petr Kubat <pkubat@redhat.com>
Signed-off-by: Jiri Moskovcak <jmoskovc@redhat.com>