*skipTrack.fit() can now incorporate longitudinal data in X matrix. Users are no
longer limited to one row of data per individual in X, but can now have one row
of data per cycle if desired.
*skipTrack.results() now produces a helpful error message if burnIn is less than fit length.
*Fit now sets all starting cij values to 1 which is much more logical and mixing occurs much quicker.
*Patch to align with parameter name changes from genMCMCDiag.
*No functionality changes.