filter ls output

[nedgonaes]

We don't have inodes yet, so ls is just a search for a prefix. All things matching the prefix are returned, and so things several levels deeper than the current folder are reported as files in that folder. Hadoop's ls takes the name portion of the uri and prints it for each path returned, so it looks like all files are sitting in /.

We can just skip the paths that are deeper for now, since HyperDex doesn't have full featured regex so we can only do ^/path/to/list/.* when we really want to do ^/path/to/list/[^/]*$.