edx/edx-platform — pull request #1641 by manuel-freire (2013-11-09 15:48:00+00:00)
Title: 298.15 K is 25 C, not 0 (0 is defined to be at 273.15)

Gratuitous sources:
https://www.google.es/search?q=0+c+in+kelvin
http://en.wikipedia.org/wiki/Kelvin

Signed-off-by: