Fixes issue zertrin/duplicity-backup/issues/41
Fixes issue zertrin/duplicity-backup/issues/41 - conf revert
Added the option to skip cleanup

I've added the option to skip cleanup by setting CLEANUP_TYPE to  'none'.
This is relevant to me because my s3 api key is not allowed to delete files,
making my backup more resistable to human error / someone getting hold of this
plaintext accessible key.
added HIDE_KEY_ID and SECRET_KEYRING options
only cleanup if CLEAN_UP_TYPE and CLEAN_UP_VARIABLE are defined
dont include --sign-key when restoring w/ hidden-enc key
Merge remote-tracking branch 'dismantl/option-updates' into dev

Conflicts:
	duplicity-backup.sh