Initial commit of xdelta diff script
Added basic framework around doing the xdelta generation

  Added creation of the xdelta3, parameter parsing, and copying of modes from
  the original files.
Added copying of mode, mtime, atime, GID, and UID

  Added code to create the deltas with the proper attributes since we will be
  using these to update the files on the target system.
Refactored the code to be a bit prettier