Initial version of the sorting script. It sorts all the photo/video
files in the tree rooted at source_directory by metadata date to
target_directory/<YYYY>/<MM>/<DD>/. Files without date metadata are
copied to target_directory/no_date/ with the original path preserved (in
case the path implies the date).

Only one version of a binary duplicate with the same name is kept. Files
with the same name and same metadata, but that are not binary dups are
copied to the target_directory/duplicates/.
Initial phototimeshift script. It will rewrite all photo/video files in
the target_directory tree that have date metadata by the amount
requested. The amount requested can be specified on the command line
with either:

1) a from and to date
  or
2) an absolute number of days to shift