Downloaded Dataset

The script has code to download the dataset from a URL if missing. Also
tracks the time downloaded through the file system modified date. This
date is then used to set the downloaded date/time.
Raw Data File Reading

  1. Implemented function to read the label files for activities and
     features of the data. These will be used to give the data more
     human friendly names.

  2. Raw read of the various data files into named variables given a
     base directory. This way it can be used to form a single data
     table for any number of data directories that have the same layout.
Data Set Reading

  1. Added a new function to read and join all of the data sets
     that we're interested in.

  2. Refactored some of the single table loading logic based on
     new constrains imposed by the single data table function.

  3. Updated main script loop.
Refactored Download Logic

Moved the download logic into a function and replaced it with an
invocation of that function. Make the code consistent in form.
Reducing Variables

Updated the script to reduce and keep only variables that match a
particular pattern - currently mean and std.
Clean Up Variable Names

  1. Cleaned up the variable names for the feature dataset instead
     of using the default behavior. Hopefully will make spliting the
     data table easier.

  2. Inlined the data table variable filter process since it was closely
     tied to the friendly variable renaming process.