Revert "PUPPET-151 Export exec's onlyif and unless configuration parameter"

This reverts commit e211aefd73f7b567cc8970e321864a13d06f95c1.
Revert "PUPPET-151 Creates parameter is configurable"

This reverts commit 3d191320867d0822435ff16e71acec98e0183f49.
Revert "PUPPET-151 Add force parameter to duplicity::file"

This reverts commit d7b0bc246c327aece6a5bb20e99c20627c082d02.