Snapshot doesn't allow injection of a FileSystem to use for the snapshot destination

[dkincaid]

The Pail.create() methods allow a FileSystem to be used in the creation of the pail. However, when creating a snapshot of a pail the only option is to include the FileSystem in the path string that is passed in for the destination. In order to keep consistency, all the methods that create a new Pail at a new path should allow a FileSystem to be given separately from the path.

[sorenmacbeth]

I'll take a look. Again, a PR would be awesome :)

[dkincaid]

I'm not exactly sure what I did, but both commits for this issue and 30 ended up on a single PR. Someday I'll figure out the proper way to do PR's on Github. Hopefully it's not too much work to tease them apart (if you even need to).