Remove setting 256 colors for solarized on terminal vim

these settings confuse the solarized colors in terminal vim, which is for example always used for git commits. without them the latest terminal vim has the perfect solarized experience. 

without those settings:
![after](https://f.cloud.github.com/assets/563961/1647389/9aa8abe4-593e-11e3-8cad-eb4077273a3e.png)

with those settings:
![before](https://f.cloud.github.com/assets/563961/1647390/9ac18812-593e-11e3-8218-3954f47fcf5e.png)


so the question is: why has it been added?