addbackup: handle file in subdirectory
The current naming scheme ('journal.backups.<file>') resulted is bad directory
name when 'file' was in a subdirectory. We now extract the directory name and
create the backupfile within it.
We plan to use file in a subdirectory for cachefile.
try:
import coverage
getattr(coverage, 'process_startup', lambda: None)()
except ImportError:
pass