Data past 2011

This is the beginning of a new function to build tables out of data
sources that are not coming from a pre-combined master data file.
Add type and credits for later data
Change count to be less dependent on attributes that change each year.
Change melt to work with arbitrary attributes
Deletions for reduntant code.
Adjust count to reflect new attributes.

Needs another refactor similar to extract_course to work with arbitrary
count.
Commented out disability code.

Inconsistencies in future years led to commenting this code out. Need a
new approach to better re-label disability data for future use.
Currently this is not used so it can be commented out without serious
consequence.
Adjust model to use two years of data.
Fixes missing to NA.
Course Performance for First Quarter GPA and Failures
Begins to load 2011_12 and 2012_13 data sets.
Unchanged.
New function to calculate tp, tn, fp, fn rates and accuracy
Beginning the course failure/grades analysis.