[deployment/basedir] Add additional logging when purging
[util/purgeable] update indentation and docs
[util/basedir] Rename from deployment

The basedir construct should be more general purpose; it has some
functionality that might be nice to reuse for purging module directories
as well.
[util/basedir] Conditionally warn about unclaimed contents
[util/basedir] Add path info to log messages
Merge pull request #196 from adrienthebo/maint/master/improve-purge-logging

Maint/master/improve purge logging