Second commit
- Added bayes_updater.m. This is a modification of bayes_updating.m and
  is generalized for use on any data set. Work in progress at the
  moment.
- Added by_user.mat and gl_mean.mat. These are inputs for
  bayes_updater.m.
Complete bayes_updater and add bayes_updater_30071

- Complete bayes_updater.m so that it mirrors functionality of
bayes_updating.m
- Added bayes_updater_30071 which looks at a specific user
- by_user.mat includes user_id data in the fifth column