MISC/COSMITS: addresses minor doc and viz style issues

- fix doc string for equalize epochs count method
- red instead of black hline for evoked plots (now that the default to black
black hlines are not easy to discern.). I prefer this to adding another compicated dict as param.
Merge pull request #484 from dengemann/fix_whitened_evoked

MISC/COSMITS: addresses minor doc and viz style issues