Step 1: Merges the training and the test sets to create one data set.
Step 2: Extracts only the measurements on the mean and standard deviation for each measurement
Added keys on data tables
Step 5: Creates a second, independent tidy data set with the average of each variable for each activity and each subject.
Clean up; removed unneccessary code
Clean up inline docs, add code to write the resultant data set into a file
Update README
Update README