Run-13 Projected Impact on Run-12 W+/W- Cross Section Ratio

Combines preliminary Run-12 W+/W- cross section ratio with current Run-13 cross section ratio.
Run-13 ratio is described here:
https://drupal.star.bnl.gov/STAR/system/files/userfiles/3754/posik01302015(1).pdf

Run-12 ratio is described here:
https://drupal.star.bnl.gov/STAR/system/files/posik-PrelimRequestAna-03272015.pdf