Fixes highlighting color for Light scheme. (fixes issue #43)

Light scheme was using base02 color for highlighting, when Solarized specs clearly state that it is base2 the one that must be used for this purpose.
 
![screen shot 2013-11-16 at 11 07 40 pm](https://f.cloud.github.com/assets/1840284/1557332/01c2be34-4f10-11e3-80b1-b318bbb95d06.png)