update readme for v0.2.0
replace scan_md5 with scan_file in :list action

scan_file is currently MUCH faster than scan_md5 due to some inefficient
code in the BucketFile#absolute_path method
add support for :grep-ing origin paths

and displaying appropriately
add support for BucketFiles with no path

FTR a BucketFile can have 0,1..n paths
get bucket and clientbucket path from Puppet

instead of guessing where they are
update .gitignore because OSX
bump version to 0.3.0