set default sha1sum to None
Nicer output for mad show
Addded ‘volume’, changed ‘backup’

* volume for the mounted volume a file is stored on
* organised backup keywords
removed basename from mongo indexable fields
Only ‘mad find’ files that have a writeable sha1sum location
Ensure sha1sum is calculated from here + some cleaning up,
Added dummy finish method
Bulk commits to mongodb, mongo flush dirs, cleaning

flush dir is the ability to remove files that have been removed from 
the bulk database
added dset - set values on a directory
Prepare to remove the SHA1SUM.META and use the time on SHA1SUM.

Current version is working.
changed host alias to volume alias
UI message & like now take arguments as logging.debug does
changed logging.warning to ui.message
Working hashing now - decided to keep the .META file + minor cleanups

marked a number of functions with deprecated warnings - these are to be
deleted at a later stage
version bump